Wireless communications system, base station, mobile station, and processing method

ABSTRACT

A communication system includes: a first communication apparatus configured to control a first wireless communication and a second wireless communication different from the first wireless communication; a second communication apparatus configured to communicate using the second communication; and a third communication apparatus configured to perform data communication with the first communication apparatus via the first wireless communication or the second wireless communication, wherein the third communication apparatus transmits to the first communication apparatus a control message that includes an available address of the third wireless communications apparatus used in the second wireless communication, the first communication apparatus notifies the second communication apparatus of the available address of the third communication apparatus, and the second communication apparatus communicate with the third communication apparatus using the address.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/725,890, filed on Oct. 5, 2017, which is a continuation applicationof International Application PCT/JP2015/063953, filed on May 14, 2015,which claims priority from International Application PCT/JP2015/061293filed on Apr. 10, 2015, the contents of each are incorporated herein byreference.

FIELD

The embodiments discussed herein relate to a wireless communicationssystem, a base station, a mobile station, and a processing method.

BACKGROUND

Mobile communications such as long term evolution (LTE) areconventionally known (e.g., refer to 3GPP TS36.300 v12.5.0, March 2015;3GPP TS36.211 v12.5.0, March 2015; 3GPP TS36.212 v12.4.0, March 2015;3GPP TS36.213 v12.5.0, March 2015; 3GPP TS36.321 v12.5.0, March 2015;3GPP TS36.322 v12.2.0, March 2015; 3GPP TS36.323 v12.3.0, March 2015;3GPP TS36.331 v12.5.0, March 2015; 3GPP TS36.413 v12.5.0, March 2015;3GPP TS36.423 v12.5.0, Mar. 2015; 3GPP TS36.425 v12.1.0, March 2015;3GPP TR36.842 v12.0.0, December 2013; 3GPP TR37.834 v12.0.0, December2013). Under LTE, aggregation for communicative cooperation with awireless local area network (WLAN) on a wireless access level is beingstudied (e.g., refer to 3GPP RWS-140027, June 2014 and 3GPP RP-140237,March 2014). Further, integration and interworking at the wireless levelbetween LTE and WLANs is being studied (e.g., refer to 3GPP RP-150510,March 2015).

A technique of transferring data from the radio resource control (RRC)layer to the media access control (MAC) layer when a WLAN is used isalso known (e.g., refer to International Publication No. 2012/121757).Another technique of sharing LTE packet data convergence protocol (PDCP)between LTE and a WLAN is also known (e.g., refer to InternationalPublication No. 2013/068787). A further technique of performing datatransmission control on the basis of quality of service (QoS)information in WLAN, etc. is also known.

SUMMARY

According to an aspect of an embodiment, a wireless communicationssystem includes a first wireless communications apparatus configured tocontrol by a controller configured to control a first wirelesscommunication, a second wireless-communication different from the firstwireless communication; a second wireless communications apparatuscapable of performing the second wireless communication; and a thirdwireless communications apparatus capable of data transmission with thefirst wireless communications apparatus via the first wirelesscommunication or the second wireless communication. The third wirelesscommunications apparatus transmits to the first wireless communicationsapparatus a control message that includes an available address of thethird wireless communications apparatus in the second wirelesscommunication. In a case where data is transmitted from the firstwireless communications apparatus to the third wireless communicationsapparatus by the second wireless communications apparatus via the secondwireless communication, a processor, which is in the first wirelesscommunication apparatus and for performing the first wirelesscommunications, transfers the data to the second wireless communicationsapparatus through an adaptation sublayer and notifies the secondwireless communications apparatus of the address acquired from thecontrol message, wherein the data is already processed in a convergencelayer for performing the first wireless communication. The secondwireless communications apparatus sets the address notified from thefirst wireless communications apparatus as a destination address andtransmits the data transferred from the first wireless communicationsapparatus to the third wireless communications apparatus via the secondwireless communication.

The object and advantages of the invention will be realized and attainedby means of the elements and combinations particularly pointed out inthe claims.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and arenot restrictive of the invention.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram depicting an example of a wireless communicationssystem according to a first embodiment;

FIG. 2 is a diagram depicting another example of the wirelesscommunications system according to the first embodiment;

FIG. 3 is a diagram depicting an example of the wireless communicationssystem according to a second embodiment;

FIG. 4 is a diagram depicting an example of a terminal according to thesecond embodiment;

FIG. 5 is a diagram depicting an example of a hardware configuration ofthe terminal according to the second embodiment;

FIG. 6 is a diagram depicting an example of the base station accordingto the second embodiment;

FIG. 7 is a diagram depicting an example of a hardware configuration ofthe base station according to the second embodiment;

FIG. 8 is a diagram depicting an example of a protocol stack in thewireless communications system according to the second embodiment;

FIG. 9 is a diagram depicting an example of a layer 2 in the wirelesscommunications system according to the second embodiment;

FIG. 10 is a diagram depicting an example of an IP header of an IPpacket that is transmitted in the wireless communications systemaccording to the second embodiment;

FIG. 11 is a diagram depicting an example of values of a ToS fieldincluded in an IP header of an IP packet transmitted in the wirelesscommunications system according to the second embodiment;

FIG. 12 is a diagram depicting an example of aggregation by LTE-A andWLAN in the wireless communications system according to the secondembodiment;

FIG. 13 is a diagram depicting an example of QoS control based on theToS field in the wireless communications system according to the secondembodiment;

FIG. 14 is a diagram depicting an example of AC classification in thewireless communications system according to the second embodiment;

FIG. 15 is a diagram depicting an example of aggregation in the wirelesscommunications system according to the second embodiment;

FIG. 16 is a diagram depicting an example of mapping to QoS class ACsapplicable to the wireless communications system according to the secondembodiment;

FIG. 17 is a flowchart depicting an example of processing by atransmitter apparatus in the wireless communications system according tothe second embodiment;

FIG. 18 is a diagram depicting an example of a case where plural EPSbearers have a same QoS class in the wireless communications systemaccording to the second embodiment;

FIG. 19 is a diagram depicting an example of implementation of an outerIP layer using a 3GPP protocol in the second embodiment;

FIG. 20 is a diagram depicting another example of implementation of theouter IP layer using a 3GPP protocol in the second embodiment;

FIG. 21 is a diagram depicting another example of implementation of theouter IP layer using a 3GPP protocol in the second embodiment;

FIG. 22 is a diagram depicting an example of implementation of the outerIP layer using a new tunnel protocol in the second embodiment;

FIG. 23 is a diagram depicting another example of implementation of theouter IP layer using a new tunnel protocol in the second embodiment;

FIG. 24 is a diagram depicting an example of implementation of the outerIP layer using a new tunnel protocol in the second embodiment;

FIG. 25 is a diagram depicting an example of a method of identifying EPSbearers using UL TFT in a wireless communications system according to athird embodiment;

FIG. 26 is a diagram depicting another example of a method ofidentifying EPS bearers using UL TFT in the wireless communicationssystem according to the third embodiment;

FIG. 27 is a diagram depicting an example of a TFT acquisition method inthe wireless communications system according to the third embodiment;

FIG. 28 is a diagram depicting an example of a method of identifying EPSbearers using DL TFT in the wireless communications system according tothe third embodiment;

FIG. 29 is a diagram depicting another example of a method ofidentifying EPS bearers using DL TFTs in the wireless communicationssystem according to the third embodiment;

FIG. 30 is a diagram depicting an example of a method of identifying EPSbearers using a virtual IP flow in the wireless communications systemaccording to the third embodiment;

FIG. 31 is a diagram depicting another example of a method ofidentifying EPS bearers using virtual IP flow in the wirelesscommunications system according to the third embodiment;

FIG. 32 is a diagram depicting an example of a method of identifying EPSbearers using VLAN in the wireless communications system according tothe third embodiment;

FIG. 33 is a diagram depicting another example of a method ofidentifying EPS bearers using VLAN in the wireless communications systemaccording to the third embodiment;

FIG. 34 is a diagram depicting an example of a method of identifying EPSbearers using GRE tunneling in the wireless communications systemaccording to the third embodiment;

FIG. 35 is a diagram depicting another example of a method ofidentifying EPS bearers using GRE tunneling in the wirelesscommunications system according to the third embodiment;

FIG. 36 is a diagram depicting an example of a method of identifying anEPS bearer by using PDCPoIP in the wireless communications systemaccording to the third embodiment;

FIG. 37 is a diagram depicting another example of a method ofidentifying EPS bearers using PDCPoIP in the wireless communicationssystem according to the third embodiment;

FIG. 38 is a diagram (part 1) describing processing for data transmittedby a WLAN in the wireless communications system according to a fourthembodiment;

FIG. 39 is a diagram (part 2) describing processing for data transmittedby a WLAN in the wireless communications system according to the fourthembodiment;

FIG. 40 is a sequence diagram depicting an example of processing in thewireless communications system according to the fourth embodiment;

FIG. 41 is a sequence diagram of notification of the MAC address by adifferent RRC message in processing in the wireless communicationssystem according to the fourth embodiment;

FIG. 42 is a sequence diagram of notification of the MAC address by adifferent RRC message in the processing in the wireless communicationssystem according to the fourth embodiment;

FIG. 43 is a sequence diagram of another example of processing in thewireless communications system according to the fourth embodiment; and

FIG. 44 is a diagram depicting an example of a packet format in an ARPapplicable to the fourth embodiment.

DESCRIPTION OF THE INVENTION

Embodiments of a wireless communications system, a base station, amobile station, and a processing method according to the presentinvention will be described in detail with reference to the accompanyingdrawings.

FIG. 1 is a diagram depicting an example of a wireless communicationssystem according to a first embodiment. As depicted in FIG. 1, awireless communications system 100 according to the first embodimentincludes a base station 110 and a mobile station 120. The wirelesscommunications system 100 is capable of data transmission between thebase station 110 and the mobile station 120 concurrently using a firstwireless communication 101 and a second wireless communication 102.

The first wireless communication 101 and the second wirelesscommunication 102 are different wireless communications (wirelesscommunication schemes). For example, the first wireless communication101 is a cellular communication such as LTE or LTE-A. For example, thesecond wireless communication 102 is a WLAN. Note that the firstwireless communication 101 and the second wireless communication 102 canbe various types of communications without limitation hereto. In theexample depicted in FIG. 1, the base station 110 is a base stationcapable of the first wireless communication 101 and the second wirelesscommunication 102 between the base station 110 and the mobile station120, for example.

When transmitting data by concurrent use of the first wirelesscommunication 101 and the first wireless communication 102, the basestation 110 and the mobile station 120 configure therebetween acommunication channel of the first wireless communication 101 fortransmission of data of the first wireless communication 101. Further,the base station 110 and the mobile station 120 configure therebetween acommunication channel of the wireless communication 102 for transmissionof data of the first wireless communication 101. The base station 110and the mobile station 120 transmit data by concurrently using thecommunication channels configured for the first wireless communication101 and the second wireless communication 102.

A downlink for transmitting data from the base station 110 to the mobilestation 120 will first be described. The base station 110 includes acontrol unit 111 and a processing unit 112. The control unit 111provides control for the first wireless communication 101. The controlunit 111 provides control for the second wireless communication 102. Forexample, the control unit 111 is a processing unit such as an RRC thatperforms wireless control between the base station 110 and the mobilestation 120. It is to be noted that the control unit 111 is not limitedto the RRC and can be any type of processing unit that provides controlfor the first wireless communication 101.

The processing unit 112 performs processing for performing the firstwireless communication 101. For example, the processing unit 112 is aprocessing unit that processes data transmitted via the first wirelesscommunication 101. For instance, the processing unit 112 is a processingunit for a data link layer, such as PDCP, radio link control (RLC), andMAC. It should be understood that the processing unit 112 is not limitedto those above and can be any type of processing unit for performing thefirst wireless communication 101.

Processing of the processing unit 112 for performing the first wirelesscommunication 101 is controlled by the control unit 111. When data istransmitted from the base station 110 to the mobile station 120 usingwireless communication via the second wireless communication 102, theprocessing unit 112 establishes a convergence layer for performing thefirst wireless communication 101. This convergence layer includesprocessing for dividing between the first wireless communication 101 andthe second wireless communication 102, data that is to be transmittedbetween the base station 110 and the mobile station 120.

For instance, the convergence layer is a PDCP layer. However, theconvergence layer is not limited to a PDCP layer and can be any type oflayer. The convergence layer may be designated as an end point, a branchpoint, a split function, or a routing function. Such a designation isnot limiting provided it means a data scheduling point between the firstwireless communication and the second wireless communication.Hereinafter, the convergence layer is used as one such generaldesignation.

For data transmitted from the base station 110 to the mobile station 120by using the second wireless communication 102, the processing unit 112transmits to the mobile station 120 by tunneling, the data for whichconvergence layer processing has been performed. The processing unit 112transmits the data as a Protocol Data Unit (PDU) whose header includes asequence number (SN), etc. added by the convergence layer processing. Asa result, data destined for the mobile station 120 can be transmitted bythe second wireless communication 102 with the sequence number includedas is. In other words, the PDU of the first wireless communication 101can be transmitted transparently by the second wireless communication102.

In contrast, the mobile station 120 can perform a reception process forthe data transmitted from the base station 110 by the first wirelesscommunication 101 and the data transmitted from the base station 110 bythe second wireless communication 102, based on a process of the firstwireless communication 10. For example, the mobile station 120 canperform sequence control based on the sequence number. As a result, datatransmission that concurrently uses the first wireless communication 101and the second wireless communication 102 becomes possible. Therefore,for example, the transmission rate of data can be improved.

Next, uplink for transmitting data from the mobile station 120 to thebase station 110 will be described. The mobile station 120 includes aprocessing unit 121. The processing unit 121, similar to the processingunit 112 of the base station 110, is a processing unit for performingthe first wireless communication 101. For example, the processing unit121 is a processing unit for a data link layer, such as PDCP, RLC, andMAC. However, the processing unit 121 is not limited to those above andcan be any type of processing unit for performing the first wirelesscommunication 101.

Processing by the processing unit 121 for performing the first wirelesscommunication 101 is controlled by the control unit 111 of the basestation 110. The processing unit 121, when transmitting data from themobile station 120 to the base station 110 by using wirelesscommunication of the second wireless communication 102, establishes theconvergence layer for performing the first wireless communication 101.The convergence layer, as described above, includes processing fordividing between the first wireless communication 101 and the secondwireless communication 102, data that is to be transmitted between thebase station 110 and the mobile station 120.

For data that is to be transmitted from the mobile station 120 to thebase station 110 by using the second wireless communication 102, theprocessing unit 121 transmits to the base station 110 by tunneling, thedata for which convergence layer processing has been performed. Theprocessing unit 121 transmits the data as a PDU whose header includes asequence number, etc. added by the convergence layer processing. As aresult, the data destined for the base station 110 can be transmitted bythe second wireless communication 102 with the sequence number includedas is.

In contrast, the base station 110 can perform sequence control for thedata transmitted from the mobile station 120 by the first wirelesscommunication 101 and the data transmitted from the mobile station 120by the second wireless communication 102, based on the sequence number.Therefore, data transmission that concurrently uses the first wirelesscommunication 101 and the second wireless communication 102 becomespossible.

In this manner, for data that is to be transmitted by the secondwireless communication 102, the transmitting station among the basestation 110 and the mobile station 120 transmits by tunneling, a PDUwhose header includes a sequence number added by convergence layerprocessing. As a result, at the receiving station, sequence controlbetween data transmitted from the mobile station 120 by the firstwireless communication 101 and data transmitted from the mobile station120 by the second wireless communication 102 can be performed based onthe sequence number. Therefore, data transmission that concurrently usesthe first wireless communication 101 and the second wirelesscommunication 102 becomes possible.

FIG. 2 is a diagram depicting another example of the wirelesscommunications system according to the first embodiment. In FIG. 2,parts identical to those depicted in FIG. 1 are designated by the samereference numerals used in FIG. 1 and explanations thereof will beomitted. In FIG. 1, although a case is described in which the basestation 110 is a base station capable of performing the first wirelesscommunication 101 and the second wireless communication 102 with themobile station 120, as depicted in FIG. 2, instead of the base station110, base stations 110A, 1106 may be provided.

The base station 110A is a base station capable of performing the firstwireless communication 101 with the mobile station 120. The base station1106 is a base station connected with the base station 110A and is abase station capable of performing the second wireless communication 102with the mobile station 120.

In the example depicted in FIG. 2, the base station 110A performs datatransmission with the mobile station 120 by using the second wirelesscommunication 102, via the base station 1106. In this case, the controlunit 111 and the processing unit 112 depicted in FIG. 1, for example,are provided in the base station 110A. Further, the control unit 111performs control of the second wireless communication 102 with themobile station 120 via the base station 1106.

First, downlink for transmitting data from the base station 110A to themobile station 120 will be described. For data that is to be transmittedto the mobile station 120 by using the second wireless communication102, the processing unit 112 of the base station 110A transmits to thebase station 1106 by tunneling, the data for which convergence layerprocessing has been performed. The processing unit 112 transmits thedata as a PDU whose header includes a sequence number, etc. added by theconvergence layer processing. As a result, the data can be transmittedto the mobile station 120 via the base stations 110A, 1106. The basestation 1106 transmits to the mobile station 120 by the second wirelesscommunication 102, the data transferred from the base station 110A.

Next, uplink for transmitting data from the mobile station 120 to thebase station 110A will be described. For data that is to be transmittedto the base station 110 by using the second wireless communication 102,the processing unit 121 of the mobile station 120 transmits to the basestation 110B by tunneling, the data for which convergence layerprocessing has been performed. The processing unit 121 transmits thedata as a PDU whose header includes a sequence number, etc. added by theconvergence layer processing. The base station 110B transfers to thebase station 110A, the data transmitted from the mobile station 120 bythe second wireless communication 102. As a result, data destined forthe base station 110A can be transmitted to the base station 110A byusing the second wireless communication 102.

In this manner, according to the wireless communications system 100according to the first embodiment, data transmission that concurrentlyuses the first wireless communication 101 and the second wirelesscommunication 102 becomes possible between the base station 110 and themobile station 120. Therefore, for example, the transmission rate ofdata can be improved.

Next, details of the wireless communications system 100 according to thefirst embodiment depicted in FIG. 1 will be described using second tofourth embodiments. The second to fourth embodiments can be regarded asexamples embodying the first embodiment described above and therefore,can be implemented in combination with the first embodiment.

FIG. 3 is a diagram depicting an example of the wireless communicationssystem according to a second embodiment. As depicted in FIG. 3, awireless communications system 300 according to the second embodimentincludes a UE 311, eNBs 321, 322, and a packet core network 330. Thewireless communications system 300 is a mobile communications systemsuch as LTE-A defined by 3GPP, for example. Nonetheless, thecommunication standard of the wireless communications system 300 is notlimited hereto.

For example, the packet core network 330 is an evolved packet core (EPC)defined under 3GPP, but is not particularly limited hereto. Note thatthe core network defined by 3GPP may be called system architectureevolution (SAE). The packet core network 330 includes an SGW 331, a PGW332, and an MME 333.

The UE 311 and the eNBs 321, 322 form a wireless access network byperforming wireless communication. The wireless access network formed bythe UE 311 and the eNBs 321, 322 is, for example, an evolved universalterrestrial radio access network (E-UTRAN) defined by 3GPP, but is notparticularly limited hereto.

The UE 311 is a terminal located within a cell of the eNB 321 andperforms wireless communication with the eNB 321. For example, the UE311 performs communication with another communication device through theeNB 321, SGW 331 and the PGW 332. For example, another communicationdevice performing communication with the UE 311 is a communicationterminal different from the UE 311, or is a server, etc. Communicationbetween the UE 311 and another communication device is, for example,data communication or audio communication, but is not particularlylimited hereto. Audio communication is, for example, voice over LTE(VoLTE), but is not particularly limited hereto.

The eNB 321 is a base station forming a cell 321 aand performingwireless communication with the UE 311 located within the cell 321 a.The eNB 321 relays communication between the UE 311 and the SGW 331. TheeNB 322 is a base station that forms a cell 322 a and performs wirelesscommunication with a UE located within the cell 322 a. The eNB 322relays communication between the UE located within the cell 322 a andthe SGW 331.

The eNB 321 and the eNB 322 may be connected to each other via aphysical or logical interface between base stations, for example. Theinterface between base stations is, for example, an X2 interface, but isnot particularly limited hereto. The eNB 321 and the SGW 331 areconnected to each other via a physical or logical interface, forexample. The interface between the eNB 321 and the SGW 331 is, forexample, an S1-U interface, but is not particularly limited hereto.

The SGW 331 is a serving gateway accommodating the eNB 321 andperforming user plane (U-plane) processing in communication via the eNB321. For example, the SGW 331 performs the U-plane processing incommunication of the UE 311. The U-plane is a function group performinguser data (packet data) transmission. The SGW 331 may accommodate theeNB 322 and perform the U-plane processing in communication via the eNB322.

The PGW 332 is a packet data network gateway for connection to anexternal network. The external network is the Internet, for example, butis not particularly limited hereto. For example, the PGW 332 relays userdata between the SGW 331 and the external network. For example, to allowthe UE 311 to transmit or receive an IP flow, the PGW 332 performs an IPaddress allocation 201 for allocating an IP address to the UE 311.

The SGW 331 and the PGW 332 are connected to each other via a physicalor logical interface, for example. The interface between the SGW 331 andthe PGW 332 is an S5 interface, for example, but is not particularlylimited hereto.

The MME (mobility management entity) 233 accommodates the eNB 321 andperforms control plane (C-plane) processing in communication via the eNB321. For example, the MME 333 performs C-plane processing incommunication of the UE 311 via the eNB 321. The C-plane is, forexample, a function group for controlling a call or a network betweendevices. For example, the C-plane is used in connection of a packetcall, configuration of a path for user data transmission, handovercontrol, etc. The MME 333 may accommodate the eNB 322 and performC-plane processing in communication via the eNB 322.

The MME 333 and the eNB 321 are connected to each other via a physicalor logical interface, for example. The interface between the MME 333 andthe eNB 321 is an S1-MME interface, for example, but is not particularlylimited thereto. The MME 333 and the SGW 331 are connected to each othervia a physical or logical interface, for example. The interface betweenthe MME 333 and the SGW 331 is an S11 interface, for example, but is notparticularly limited hereto.

In the wireless communications system 300, an IP flow transmitted fromor received by the UE 311 is classified into (allocated to) EPS bearers341 to 34 n and is transmitted via the PGW 332 and the SGW 331. The EPSbearers 341 to 34 n are the IP flow in an evolved packet system (EPS).The EPS bearers 341 to 34 n are in the form of radio bearers 351 to 35 nin the wireless access network formed by the UE 311 and the eNB 321,322. Overall communication control such as configuration of the EPSbearers 341 to 34 n, security configuration, and mobility management isprovided by the MME 333.

The IP flow classified into the EPS bearers 341 to 34 n is transmittedthrough a GPRS tunneling protocol (GTP) tunnel configured between nodes,for example, in an LTE network. The EPS bearers 341 to 34 n are uniquelymapped to the radio bearers 351 to 35 n, respectively, for wirelesstransmission that takes QoS into account.

In the communication between the UE 311 and the eNB 321 of the wirelesscommunications system 300, an LTE-A and WLAN aggregation is carried outto transmit LTE-A traffic using LTE-A and a WLAN concurrently. Thisenables the traffic between the UE 311 and the eNB 321 to be distributedto LTE-A and WLAN concurrently, to achieve an improvement in throughputin the wireless communications system 300. The first wirelesscommunication 101 depicted in FIG. 1 can be LTE-A wirelesscommunication, for example. The second wireless communication 102depicted in FIG. 1 can be WLAN wireless communication, for example. TheLTE-A and WLAN aggregation will be described later.

It is to be understood that the designation of aggregation is merely anexample and is often used to mean use of plural communicationfrequencies (carriers). Other than aggregation, integration is oftenused as a designation to mean different systems are integrated forplural use. Hereinafter, aggregation is used as a general designation.

The base stations 110, 110A, and 110B depicted in FIGS. 1 and 2 can beimplemented by the eNBs 321, 322, for example. The mobile station 120depicted in FIGS. 1 and 2 can be implemented by the UE 311, for example.

FIG. 4 is a diagram depicting an example of the terminal according tothe second embodiment. The UE 211 depicted in FIG. 3 can be implementedby a terminal 400 depicted in FIG. 4, for example. The terminal 400includes a wireless communications unit 410, a control unit 420, and astorage unit 430. The wireless communications unit 410 includes awireless transmitting unit 411 and a wireless receiving unit 412. Theseunits are connected with one another so as to enable unidirectional orbidirectional input or output of signals or data. The wirelesscommunications unit 410 is capable of, for example, LTE-A wirelesscommunication (the first wireless communication 101) and WLAN wirelesscommunication (the second wireless communication 102).

The wireless transmitting unit 411 transmits user data or a controlsignal through wireless communication via an antenna. A wireless signaltransmitted from the wireless transmitting unit 411 can includearbitrary user data, control information, etc. (that has been encoded,modulated, etc.). The wireless receiving unit 412 receives user data ora control signal through wireless communication via an antenna. Awireless signal received by the wireless receiving unit 412 can includearbitrary user data, control information, etc. (that has been encoded,modulated, etc.). A common antenna may be used for transmitting andreceiving.

The control unit 420 outputs to the wireless transmitting unit 411, userdata, a control signal, etc. to be transmitted to another wirelessstation. The control unit 420 acquires user data, a control signal, etc.received by the wireless receiving unit 412. The control unit 420inputs/outputs user data, control information, a program, etc. from/tothe storage unit 430 described later. The control unit 420 inputsfrom/outputs to the communications unit 410, user data, a controlsignal, etc. transmitted to or received from another communicationdevice, etc. In addition to the above, the control unit 420 providesvarious types of control in the terminal 400. The storage unit 430stores various types of information such as user data, controlinformation, and a program.

The processing unit 121 of the mobile station 120 depicted in FIG. 1 canbe implemented by the control unit 420, for example.

FIG. 5 is a diagram depicting an example of a hardware configuration ofthe terminal according to the second embodiment. The terminal 400depicted in FIG. 4 can be implemented by a terminal 500 depicted in FIG.5, for example. The terminal 500 includes, for example, an antenna 511,an RF circuit 512, a processor 513, and a memory 514. These componentsare connected with one another so as to enable input/output of varioussignals or data via a bus, for example.

The antenna 511 includes a transmitting antenna that transmits awireless signal and a receiving antenna that receives a wireless signal.The antenna 511 may be a common antenna that sends and receives awireless signal. The RF circuit 512 performs radio frequency (RF)processing for a signal received by or sent from the antenna 511. The RFprocessing includes, for example, frequency conversion between abaseband and a RF band.

The processor 513 is, for example, a central processing unit (CPU) or adigital signal processor (DSP). The processor 513 may be implemented bya digital electronic circuit such as an application specific integratedcircuit (ASIC), a field programmable gate array (FPGA), and a largescale integration (LSI).

The memory 514 can be implemented, for example, by a random accessmemory (RAM) such as a synchronous dynamic random access memory (SDRAM),a read only memory (ROM), or a flash memory. The memory 514 stores userdata, control information, a program, etc., for example.

The wireless communications unit 410 depicted in FIG. 4 can beimplemented by the antenna 511 and the RF circuit 512, for example. Thecontrol unit 420 depicted in FIG. 4 can be implemented by the processor513, for example. The storage unit 430 depicted in FIG. 4 can beimplemented by the memory 514, for example.

FIG. 6 is a diagram depicting an example of the base station accordingto the second embodiment. The eNBs 321, 322 depicted in FIG. 3 can eachbe implemented by a base station 600 depicted in FIG. 6, for example. Asdepicted in FIG. 6, the base station 600 includes, for example, awireless communications unit 610, a control unit 620, a storage unit630, and a communications unit 640. The wireless communications unit 610includes a wireless transmitting unit 611 and a wireless receiving unit612. These units are connected with one another so as to enable aunidirectional or bidirectional input or output of signals or data. Thewireless communications unit 610 is capable of, for example, LTE-Awireless communication (the first wireless communication 101) and WLANwireless communication (the second wireless communication 102).

The wireless transmitting unit 611 transmits user data, a controlsignal, etc. through wireless communication via an antenna. A wirelesssignal transmitted from the wireless transmitting unit 611 can includearbitrary user data, control information, etc. (that has been encoded,modulated, etc.). The wireless receiving unit 612 receives user data, acontrol signal, etc. through wireless communication via an antenna. Awireless signal received by the wireless receiving unit 612 can includearbitrary user data, control information, etc. (that has been encoded,modulated, etc.). A common antenna may be used for transmitting andreceiving.

The control unit 620 outputs to the wireless transmitting unit 611, userdata, a control signal, etc. to be transmitted to another wirelessstation. The control unit 320 acquires user data, a control signal, etc.received by the wireless receiving unit 612. The control unit 620inputs/outputs user data, control information, a program, etc. from/tothe storage unit 630 described later. The control unit 620 inputsfrom/outputs to the communications unit 640 described later, user data,a control signal, etc. transmitted to or received from anothercommunication device, etc. In addition to the above, the control unit620 provides various types of control in the base station 600.

The storage unit 630 stores various types of information such as userdata, control information, and a program. With respect to anothercommunication device, the communications unit 640 transmits/receivesuser data, a control signal, etc. by a wired signal, for example.

The control unit 111 and the processing unit 112 of the base station 110depicted in FIG. 1 can be implemented by the control unit 620, forexample.

FIG. 7 is a diagram depicting an example of a hardware configuration ofthe base station according to the second embodiment. The base station600 depicted in FIG. 6 may be implemented by a base station 700 depictedin FIG. 7, for example. The base station 700 includes an antenna 711, anRF circuit 712, a processor 713, a memory 714, and a network IF 715.These components are connected to one another so as to enableinput/output of various signals, data, etc. via a bus, for example.

The antenna 711 includes a transmitting antenna that transmits awireless signal and a receiving antenna that receives a wireless signal.The antenna 711 may be a common antenna that transmits and receiveswireless signals. The RF circuit 712 performs RF processing for a signalreceived by or transmitted from the antenna 711. The RF processingincludes, for example, frequency conversion between a baseband and a RFband.

The processor 713 is, for example, a CPU or a DSP. The processor 713 maybe implemented by a digital electronic circuit such as ASIC, FPGA, andLSI.

The memory 714 can be implemented by, for example, RAM such as SDRAM,ROM, or the flash memory. The memory 714 stores user data, controlinformation, a program, etc., for example.

The network IF 715 is, for example, a communication interface performingwired communication with a network. The network IF 715 may include an Xninterface for performing wired communication with a base station, forexample.

The wireless communications unit 610 depicted in FIG. 6 can beimplemented by the antenna 711 and the RF circuit 712, for example. Thecontrol unit 620 depicted in FIG. 6 can be implemented by the processor713, for example. The storage unit 630 depicted in FIG. 6 can beimplemented by the memory 714, for example. The communications unit 640depicted in FIG. 6 can be implemented by the network IF 715, forexample.

FIG. 8 is a diagram depicting an example of a protocol stack in thewireless communications system according to the second embodiment. Aprotocol stack 800 depicted in FIG. 8, for example, can be applied tothe wireless communications system 300 according to the secondembodiment. The protocol stack 800 is an LTE-A protocol stack definedunder 3GPP. Layer groups 801 to 805 are layer groups showing respectiveprocesses at the UE 311, eNB 321, SGW 331, PGW 332, and an externalnetwork server, respectively.

In the case of transmitting an IP flow in the wireless communicationssystem 300, IP flow filtering is carried out to handle each IP flow inaccordance with the QoS class. For example, for a downlink where the UE311 receives an IP flow, the PGW 332 performs packet filtering withrespect to the IP flow and classifies the IP flow into the EPS bearers341 to 34 n.

For an uplink where the UE 311 transmits an IP flow, the PGW 332notifies the UE 311 of a packet filtering rule. On the basis of thefiltering rule notified from the PGW 332, the UE 311 applies packetfiltering to the IP flow and classifies the IP flow into the EPS bearers341 to 34 n.

For example, in the uplink, the PGW 332 performs IP flow filtering by afilter layer (Filter) 811 included in an IP layer (IP) among a layergroup 804 of the PGW 332. In the downlink, the UE 311 performs IP flowfiltering by a filter layer (Filter) 812 included in an IP layer (IP)among a layer group 801 of the UE 311.

To perform QoS control (QoS management) by a router in the LTE network,the PGW 332 (case of downlink) or the UE 311 (case of uplink) configuresa QoS value in a Type of Service (ToS) field of an IP packet header.

The packet filtering by the PGW 332 or the UE 311 is performedutilizing, e.g., a 5-tuple (source/destination IP addresses,source/destination port numbers, and protocol type). The filtering rulein the packet filtering is called a traffic flow template (TFT), forexample. Some of the EPS bearers 341 to 34 n may not have a TFTconfigured therefor.

When the IP flow filtering is carried out using TFT, the IP flow can beclassified into at most 11 different EPS bearers. One bearer among theEPS bearers 341 to 34 n is called default bearer. The default bearer isgenerated when the PGW 332 allocates an IP address to the UE 311, andcontinually exists until the IP address allocated to the UE 311 isreleased. Bearers other than the default bearer among the EPS bearers341 to 34 n are called dedicated bearers. The dedicated bearers can besuitably generated and released depending on the situation oftransmitted user data.

FIG. 9 is a diagram depicting an example of a layer 2 in the wirelesscommunications system according to the second embodiment. In thewireless communications system 300 according to the second embodiment,e.g., processing depicted in FIG. 9 can be applied as the processing ofthe layer 2. The processing depicted in FIG. 9 is processing of an LTE-Alayer 2 defined by 3GPP. As depicted in FIG. 9, the LTE-A layer 2includes a PDCP 910, an RLC 920, and a MAC 930.

The PDCP 910 includes robust header compression (ROHC) for headercompression of inflow IP datagram or processing related to security. Thesecurity-related processing includes ciphering and integrity protection,for example. In normal LTE-A communication, these processes of the PDCP910 are performed on user data and the user data is forwarded to a lowerlayer (e.g., a layer 1).

In the case of carrying out dual connectivity, for example, the UE 311is capable of simultaneous communication with at most two base stations(e.g., eNBs 321, 322). A master cell group (MCG) bearer 901 is a radiobearer of a main base station.

The MCG bearer 901 can be accompanied by a split bearer 902 and asecondary cell group (SCG) bearer 903. In the case of using the splitbearer 902, when user data is forwarded from the layer 2 to a lowerlayer (e.g. layer 1), it is possible to select whether the user data isto be forwarded to only one base station or to two base stations.

The RLC 920 includes primary processing prior to wireless transmissionof user data. For example, the RLC 920 includes user data segmentation(segm.) for adjusting the user data to a size that depends on radioquality. The RLC 920 may include, e.g., an automatic repeat request(ARQ) for retransmission of user data failing in error correction at alower layer. When the user data is forwarded to the lower layer, the EPSbearers are mapped to corresponding logical channels and wirelesslytransmitted.

The MAC 930 includes wireless transmission control. For example, the MAC930 includes processing of performing packet scheduling and carrying outa hybrid automatic repeat request (HARQ) of transmitted data. HARQ iscarried out for each carrier to be aggregated in carrier aggregation.

In the MAC 930, the sender applies a logical channel identifier (LCID)to a MAC service data unit (SDU) that is user data, for transmission. Inthe MAC 930, the receiver converts radio bearers into EPS bearers usingthe LCID applied by the sender.

FIG. 10 is a diagram depicting an example of an IP header of an IPpacket that is transmitted in the wireless communications systemaccording to the second embodiment. In the wireless communicationssystem 300 according to the second embodiment, an IP packet having an IPheader 1000 depicted in FIG. 10, for example, is transmitted. The IPheader 1000 includes, for example, a source address 1001 indicating asource and a destination address 1002 indicating a destination.

The IP header 1000 includes a ToS field 1003 for performing QoS. Theabove-described QoS control is performed on the basis of values of theToS field 1003, for example. Further, the IP header 1000 includes aprotocol field 1004 storing a protocol number of a transport layercorresponding to an upper layer.

FIG. 11 is a diagram depicting an example of the values of the ToS fieldincluded in the IP header of the IP packet that is transmitted in thewireless communications system according to the second embodiment.“First 3 bits” in a table 1100 depicted in FIG. 11 shows an IPprecedence corresponding to the first 3 bits in the ToS field 1003depicted in FIG. 9, allowing 2̂3=8 different patterns. In the table 1100,the 8 different patterns show that upper patterns have higherpriorities.

For example, “111” having a highest priority in the IP precedence of theToS field 1003 shows that the IP packet corresponds to network control,and is reserved for control such as routing. “110” having a secondhighest priority in the IP precedence of the ToS field 1003 shows thatthe IP packet corresponds to internet control, and is reserved forcontrol such as routing.

In the example of FIG. 11, although a case has been described where theIP precedence of the ToS field 1003 is used as the QoS priorityinformation, the QoS priority information is not limited hereto and adifferentiated service code point (DSCP) field, for example, may beused. DSCP is a field corresponding to first 6 bits in the ToS field1003.

FIG. 12 is a diagram depicting an example of aggregation by LTE-A andWLAN in the wireless communications system according to the secondembodiment. Layer 2 processing in the LTE-A and WLAN aggregation isbased on, for example, the above-described dual connectivity processing,taking into account LTE-A backward compatibility.

An IP flow 1201 is an IP flow by a hypertext transfer protocol (HTTP)between the UE 311 and the eNB 321. An IP flow 1202 is an IP flow by afile transfer protocol (FTP) between the UE 311 and eNB 321.

Non-aggregation processing 1211 shows processing in a case oftransmitting the IP flows 1201, 1202 by LTE-A without offloading to aWLAN. This non-aggregation processing 1211 corresponds to datatransmission that uses wireless communication by the first wirelesscommunication 101 depicted in FIG. 1. In the non-aggregation processing1211, each of the IP flows 1201, 1202 undergoes PDCP, RLC, LTE-MAC, andLTE-PHY processing in the mentioned sequence. These PDCP, RLC, LTE-MACare, for example, PDCP 910, RLC 920, and MAC 930, respectively, depictedin FIG. 9. The LTE-PHY is a physical layer under LTE-A.

Aggregation processing 1212 depicts processing in a case in which the IPflows 1201, 1202 are transmitted using LTE-A and WLAN concurrently. Theaggregation processing 1212 corresponds to the transmission of datausing wireless communication by the first wireless communication 101 andthe second wireless communication 102 depicted in FIG. 1.

In the aggregation processing 1212, the IP flow 1201 is divided by PDCPinto packets to be transmitted by LTE-A and packets to be transmitted byWLAN. RLC, LTE-MAC, and LTE-PHY processes for the packets to betransmitted by LTE-A of the IP flow 1201 are sequentially performed.

Further, after the PDCP process, tunneling is performed by transmittingto the WLAN side, the packets that are to be transmitted by WLAN of theIP flow 1201 with an outer IP header by an outer IP layer. The outer IPheader, for example, is a copy of the IP header added by the upper IPlayer of the PDCP and is an IP header that is not ciphered by PDCP. Forpackets transferred to the WLAN side and having an outer IP header ofthe IP flow 1201, 0.11× MAC and 0.11× PHY processes are sequentiallyperformed; 0.11× MAC and 0.11× PHY are a MAC layer and a PHY inWLAN(802.11×), respectively.

The outer IP layer can also be provided on a secondary base station(e.g., a secondary eNB 323) side. In other words, to add the outer IPheader, information to be communicated (parameters, etc.) may benotified from a master base station (e.g., the eNB 321) to the secondarybase station. A detailed example of a parameter will be described. In asecond wireless communications system (e.g., WLAN), a telecommunicationscarrier (operator) is assumed to build a private IP network and sincethe IP header version can be independently determined, notification isnot required. The header length is the PDU length of a first wirelesscommunications system (e.g., LTE-A) and therefore, notification is notrequired. Regarding TOS, QoS information of the first wirelesscommunications system has to be taken over and therefore, notificationis desirable. Therefore, for the QoS information used by the firstwireless communications system, for example, a QCI value is notified. Atthe second wireless communications system, reconversion from the QCIvalue into a TOS value is performed and the acquired value is set intothe TOS field of the outer IP header. A fragmentation related ID, IPflag, and offset field are determined by the second wirelesscommunications system alone and therefore, notification is not required.The protocol number can be independently determined by the secondwireless communications system as described hereinafter and therefore,notification is not required. The header checksum is a value calculatedbased on the contents of the header and therefore, notification is notrequired.

In this manner, notification of a ToS value related to QoS control fromthe first wireless communications system to the second wirelesscommunications system is desirable. Further, since scheduling accordingto QoS class is performed, the maximum communication rate (AggregatedMaximum Bit Rate (AMBR) supported by the mobile station, the Time toWait (TTW) for controlling the delay time, and a guaranteed band(Guaranteed Bit Rate (GBR)), etc. may be notified. In this manner, atthe secondary base station, cases of an IP header need not be a copy ofan inner IP header.

Further, in the aggregation processing 1212, the IP flow 1202, similarto the IP flow 1201, is divided by PDCP into packets to be transmittedby LTE-A and packets to be transmitted by WLAN. RLC, LTE-MAC, andLTE-PHY processes are sequentially performed for the packets to betransmitted by LTE-A of the IP flow 1202.

Further, after the PDCP process, tunneling is performed by transmittingto the WLAN side, the packets that are to be transmitted by WLAN of theIP flow 1202 with an outer IP header by the outer IP layer. The outer IPheader, for example, is a copy of the IP header added by the upper IPlayer of the PDCP and is an IP header that is not ciphered by PDCP. Forpackets transferred to the WLAN side and having an outer IP header ofthe IP flow 1202, 0.11×MAC and 0.11×PHY processes are sequentiallyperformed.

Under LTE-A, the IP flow is classified into bearers and is managed asbearers. On the contrary, in 802.11× of the institute of electrical andelectronics engineers (IEEE), in one type of WLAN, for example, the IPflow is managed to be as the IP flow itself, not as bearers. Thisrequires, for example, mapping management 1220 that manages mapping ofwhich bearer belongs to which L2 layer, to thereby perform thenon-aggregation processing 1211 and the aggregation processing 1212 at ahigh speed.

The mapping management 1220 is performed by the RRC that provideswireless control between the UE 311 and the eNB 321, for example. TheRRC manages the radio bearers to thereby support, on a radio bearerlevel, the non-aggregation processing 1211 that uses LTE-A wirelesscommunication and the aggregation processing 1212 that uses WLANwireless communication. In the example depicted in FIG. 12, the IP flow1201 with IP flow ID=0 in HTTP is managed as a bearer with bearer ID=0,whereas the IP flow 1202 with IP flow ID=0 in FTP is managed as a bearerwith bearer ID=1.

The wireless communications system 300 according to the secondembodiment adds an outer IP header to packets that are to be transferredto a WLAN. As a result, transmission of LTE-A traffic in the WLANbecomes possible. Further, in the WLAN, the ToS fields included in thetransferred IP flows 1201, 1202 can be referred to.

For example, in the QoS under IEEE 802.11e, the ToS field of the IPheader is referred to whereby the IP flow is aggregated into 4 types ofaccess categories (ACs) and QoS is managed. In the wirelesscommunications system 300, in the WLAN, the ToS fields included in thetransferred IP flows 1201, 1202 are referred to and QoS processing basedon the ToS fields can be performed. Therefore, in the aggregationprocessing 1212, support of the QoS in the WLAN becomes possible.

In this manner, when performing aggregation using LTE-A and WLANconcurrently, the source eNB 321 adds to data after processing by PDCPfor transmission using WLAN, an outer IP header that includes servicequality information prior to the PDCP processing.

The service quality information, for example, is QoS informationindicating transmission priority levels of a service class of data, etc.For example, although the service quality information can be the ToSfield described above, the service quality information is not limitedhereto and can be various types of information indicating thetransmission priority level of dat. For example, in a virtual local areanetwork (VLAN), a field specifying the QoS is provided in a VLAN tag.More generally, the QoS information is 5-tuple information. 5-tuplerefers to source IP address and port number, destination IP address andport number, and protocol type.

For example, when LTE data is transferred to a WLAN under LTE wirelesscontrol and processing such as ciphering of the header of the data isperformed by PDCP, etc., the QoS information included in the data cannotbe referred to in the WLAN. Therefore, in the WLAN, there are cases inwhich transmission control of the data cannot be performed based in theQoS information and the communication quality decreases when aggregationis performed using LTE-A and WLAN concurrently.

In contrast, since an outer IP header including service qualityinformation is added to the data that is to be transferred to the WLAN,in the WLAN processing, transmission control based on the servicequality information becomes possible. Transmission control based on theservice quality information, for example, is QoS control of controllingthe priority level according to the service quality information.Nonetheless, transmission control based on the service qualityinformation is not limited hereto and can be various types of control.

Note that in the aggregation processing 1212, for example, cipheringprocessing in a WLAN is performed on user data transferred to the WLAN.Therefore, even if the user data is transferred to a WLAN without PDCPciphering processing, the user data can be prevented from beingtransmitted between the eNB 321 and the UE 211 without being ciphered.

For WLAN ciphering, for example, advanced encryption standard (AES),temporal key integrity protocol (TKIP), wired equivalent privacy (WEP),etc. can be used.

In the example of FIG. 11, although a case has been described where,when performing the aggregation processing 1212, the IP flows 1201, 1202do not pass through RLC and LTE-MAC with PDCP as a convergence layer(branch point), such processing is not limited hereto. For example, theprocessing may be such that, when performing the aggregation processing1212, the IP flows 1201, 1202 pass through not only PDCP but alsothrough RLC and LTE-MAC, with RLC or LTE-MAC that is a lower layer ofPDCP being the convergence layer (branch point). In this manner, theprocessing unit that establishes the convergence point (branch point)when transferring to WLAN may be a processing unit of RLC or LTE-MACwithout being limited to the processing of PDCP.

The data link layer (layer 2) of PDCP, RLC, LTE-MAC, etc. can grasp thecommunication congestion state in a wireless section between the UE 311and the eNB 321. Thus, by establishing the convergence layer in the datalink layer for transferring to a WLAN, it can be determined, forexample, whether to execute the aggregation processing 1212, dependingon the communication congestion in the wireless section between the UE311 and the eNB 321.

In the aggregation processing 1212, the outer IP layer adding the outerIP header to the packets, for example, is provided as a part of the PDCPlayer. However, as described hereinafter, the outer IP layer may beprovided as a lower layer of the PDCP.

FIG. 13 is a diagram depicting an example of QoS control based on theToS field in the wireless communications system according to the secondembodiment. As an example, case will be described where the eNB 321 hasa WLAN communication function and an IP packet 1301 is transmitted fromthe eNB 321 to the UE 311. Based on the ToS field in the IP header ofthe IP packet 1301, the eNB 321 classifies the IP packet 1301 into ACs1311 to 1314 of voice, video, best effort, and background, respectively.

In the wireless communications system 300, when aggregation is performedusing LTE-A and a WLAN concurrently, an outer IP header is added to apacket (PDCP packet) processed by the PDCP layer and transferred to theWLAN. Therefore, in the WLAN processing, the eNB 321 can refer to theToS field included in the outer IP header of the IP packet 1301 andperform AC classification based on the ToS 7 field.

Although a case has been described where the eNB 321 has the WLANcommunication function, the same applies to a case where the eNB 321transmits an IP flow to a WLAN access point to thereby performaggregation using LTE-A and the WLAN concurrently. Although a case(downlink) has also been described where the packet 1301 is transmittedfrom the eNB 321 to the UE 311, the same applies to a case (uplink)where the IP packet 1301 is transmitted from the UE 311 to the eNB 321.

FIG. 14 is a diagram depicting an example of the AC classification inthe wireless communications system according to the second embodiment.In FIG. 14, parts identical to those depicted in FIG. 13 are designatedby the same reference numerals used in FIG, 13 and will not again bedescribed.

In FIG. 14, a case is described in which the eNB 321 has a WLANcommunications function. IP packets 1401, 1402 are packets transmittedby the eNB 321 to a WLAN in the aggregation using LTE-A and the WLANconcurrently. The IP packets 1401, 1402 are an HTTP IP packet and a FTPIP packet, respectively.

The eNB 321 performs ToS value analysis classification 1410 by which theIP packets 1401, 1402 are classified into any one of the ACs 1211 to1214, based on the values of the ToS field included the IP header. Inthe example of FIG. 14, the eNB 321 classifies the IP packet 1401 intothe AC 1413 (best effort) and classifies the IP packet 1402 into the AC1414 (background). The eNB 321 then transmits to the UE 311 through aWLAN, the IP packets 1401, 1402 for which the ToS value analysisclassification 1410 has been performed.

In mapping management 1420 by RRC between the eNB 321 and UE 311, the IPpacket 1401 of HTTP is managed as IP flow ID=AC=2, bearer ID=0. AC=2represents AC1213 (best effort). In the mapping management 1420, the IPpacket 1402 of FTP is managed as IP flow ID=AC=3, bearer ID=1. AC=3represents AC1214 (background).

The UE 311 performs ToS value analysis classification 1330(declassification) corresponding to the ToS value analysisclassification 1410 (classification) on the eNB 321 side, to therebyterminate the IP packets 1401, 1402 by PDCP.

Although a case (downlink) has been described where the packets 1401,1402 are sent from the eNB 321 to the UE 311, the same applies to a case(uplink) where the IP packets 1401, 1402 are sent from the UE 311 to theeNB 321.

FIG. 15 is a diagram depicting an example of aggregation in the wirelesscommunications system according to the second embodiment. In FIG. 15, acase of downlink will be described where aggregation using LTE-A and aWLAN concurrently is performed in a WLAN standalone configuration usinga secondary eNB 323 having eNB and WLAN communication functions(eNB+WLAN), and the eNB 321 acts as a master eNB.

This aggregation is data transmission concurrently using the firstwireless communication 101 and the second wireless communication 102depicted in FIG. 1. The secondary eNB 323, for example, is a basestation capable of communication with the eNB 321 via the interfacebetween base stations such as an X2 interface for example and capable ofWLAN communication with the UE 311.

In the example depicted in FIG. 15, a case will be described where n(e.g., n=10) EPS bearers 1500 to 150 n are configured for communicationbetween the eNB 321 and the UE 311, the EPS bearers 1500 to 150 n beingdivided to LTE-A and the WLAN and transmitted. Only some of the EPSbearers 1500 to 150 n may be divided to LTE-A and the WLAN andtransmitted. In the example depicted in FIG. 15, the EPS bearers 1500 to150 n are downlink direction bearers from the eNB 321 toward the UE 311.Although in FIG. 15, a case will be described where n EPS bearers 1500to 150 n are configured, the number of the EPS bearers to be configuredis arbitrary.

The EPS bearers 1500 to 150 n are n+1 EPS bearers having EPS bearer IDs(EBIs) of 0 to n, respectively. A source (src IP) of all the EPS bearers1500 to 150 n is a core network (CN). A destination (dst IP) of the EPSbearers 1500 to 150 n is the UE 311 (UE).

In the case of transferring packets of the EPS bearers 1500 to 150 n toa WLAN, the eNB 321 transfers the packets to the secondary eNB 323, viaPDCP layers 1410 to 141 n, respectively. That is, the eNB 321 controlsthe transfer to the WLAN of the EPS bearers 1500 to 150 n by the layer 2(PDCP in the example depicted in FIG. 15) of LTE-A.

At this time, the eNB 321 adds an outer IP header to the packets thatare in each of the EPS bearers 1500 to 150 n and that are to betransferred to the WLAN. As a result, the EPS bearers 1500 to 150 ntransfer the packets to the secondary eNB 323 as IP packets. In otherwords, the EPS bearers 1500 to 150 n transfer to the WLAN, the packetsin a state in which the ToS field (QoS information) is included and theouter IP header is not ciphered.

Further, the value of a protocol field (e.g., the protocol field 1004depicted in FIG. 10) in the outer IP header can be, for example, “99”(any private encryption scheme). However, the value of the protocolfield in the outer IP header is not limited to “99”, “and may be “61”(any host internal protocol), “63” (any local network), “114” (any 0-hopprotocol), etc.

Transfer of the EPS bearers 1500 to 150 n from the eNB 321 to thesecondary eNB 323, for example, can be performed the same as a LTE-Ahandover. For example, the transfer of the EPS bearers 1500 to 150 nfrom the eNB 321 to the secondary eNB 323 can be performed using GTPtunnels 1520 to 152 n between the eNB 321 and the secondary eNB 323. TheGTP tunnels 1520 to 152 n are GTP tunnels configured for each of the EPSbearers between the eNB 321 and the secondary eNB 323. However, thistransfer is not limited to GTP tunnels and can be performed by variousmethods such as Ethernet (registered trademark), etc.

For packets that are in each of the EPS bearers 1500 to 150 n and thatare to be transmitted by LTE-A, the eNB 321 sequentially performs RLC,MAC, and PHY processing and wirelessly transmits the packets to the UE311 by LTE-A without adding an outer IP header. The UE 311 receives thepackets transmitted from the eNB 321 by LTE-A by performing processingby PHY, MAC, RLC, and PDCP (the PDCP layers 1570 to 157 n).

The secondary eNB 323 receives the EPS bearers 1500 to 150 n transferredfrom the eNB 321 via the GTP tunnels 1520 to 152 n, respectively. Thesecondary eNB 323 performs AC classification 1540 for the IP packetscorresponding to the received EPS bearers 1500 to 150 n, based on theToS field included in the IP header of each of the IP packets.

The AC classification 1540 is processing by a WLAN (802.11e) function inthe secondary eNB 323. By the AC classification 1540, for example, asdepicted in FIG. 13, the IP packets are classified into an AC of voice(VO), video (VI), best effort (BE), and background (BK).

The secondary eNB 323 transmits the IP packets classified by the ACclassification 1540 to the UE 311, via the WLAN 1550. In this case, aService Set Identifier (SSID) in the WLAN 1550 can be, for example,“offload”.

The UE 311 performs the AC declassification 1560 of the IP packetsreceived via the WLAN 1550, based on the ToS field included in the outerIP header of the IP packets. The AC declassification 1560 is processingby the WLAN (802.11e) function in the UE 311.

The UE 311 reclassifies the IP packets received by the ACdeclassification 1560 into the EPS bearers 1500 to 150 n based onclassified ACs. The UE 311 processes and receives the reclassified EPSbearers 1500 to 150 n by the PDCP layers 1570 to 157 n.

A layer group 1551 indicates protocols of the IP packet received by theUE 311 by the PDCP layers 1570 to 157 n. As indicated by the layer group1551, data transmitted by the WLAN is data processed by an applicationlayer (APP), a TCP/UDP layer, the IP layer (inner layer), the PDCPlayer, and the outer IP layer. The data (hatched portion) by theapplication layer, the TCP/UDP layer, and the IP layer is encrypted byPDCP layer processing and transmitted.

The UE 311 removes the outer IP header added to the received IP packets.A layer group 1552 indicates protocols of PDCP packets acquired byremoving the outer IP header from the IP packets received by the UE 311.The PDCP packets from the eNB 321 are transmitted using tunneling by theouter IP layer whereby, as indicated by the layer group 1552, the UE 311can receive, as PDCP packets, data transmitted by the WLAN.

A layer group 1553 indicates protocols of the PDCP packets received fromthe eNB 321 by LTE-A by the UE 311. As indicated by the layer group1553, the eNB 321 transmits to the UE 311, the PDCP packets as iswithout adding an outer IP header to the PDCP packets.

The UE 311 performs sequence control between the PDCP packets receivedby the WLAN and the PDCP packets received by LTE-A, based on thesequence numbers included in the headers of the PDCP packets. Thesequence numbers included in the headers of the PDCP packets are thesequence numbers included in the headers added to the data by processingby the PDCP layer.

As a result, the UE 311 can correctly arrange the PDCP packets receivedby the WLAN and the PDCP packets received by LTE-A in sequence and theeNB 321 can receive the data divided into LTE-A and the WLAN andtransmitted.

In this manner, in the wireless communications system 300, when the EPSbearers 1500 to 150 n are divided into LTE-A and a WLAN and transmitted,the PDCP packet transmitted by the WLAN can be transmitted by tunnelingby an outer IP. As a result, at the receiver, the data transmitted bythe WLAN can be received as PDCP packets and the PDCP sequence numberscan be used to perform sequence control between the packets received byLTE-A and the packets received by the WLAN. Therefore, data transmissionconcurrently using LTE-A and a WLAN becomes possible.

Further, by adding an outer IP header that is a copy of the inner IPheader to the PDCP packets transmitted by the WLAN and performingtunneling, at the secondary eNB 323, it becomes possible to refer to theToS fields of the outer IP headers of the IP packets. Therefore, for thedata transmitted by the WLAN 1550, the AC classification 1540 can beperformed based on the ToS field and QoS control can be performedaccording to the nature of the traffic.

At the WLAN 1550, a priority value in a VLAN tag defined by IEEE 802.1qcan referred to and AC classification can be performed. The VLAN tag isthe identifier of the VLAN.

In FIG. 15, a case is described in which the eNB 321 becomes the mastereNB and aggregation is performed using LTE-A and a WLAN concurrently ina WLAN standalone configuration using the secondary eNB 323 having eNBand WLAN communication functions (eNB+WLAN). However, the aggregation isnot limited hereto and, for example, the eNB 321 may perform theaggregation in a configuration also having a WLAN communication function(eNB+WLAN). In this case, communication with the UE 311 by the WLAN isalso performed by the eNB 321 and the secondary eNB 323 need not beused.

FIG. 16 is a diagram depicting an example of mapping to QoS class ACsapplicable to the wireless communications system according to the secondembodiment. The WLAN sender (e.g. the secondary eNB 323) classifies intoACs, EPS bearers that are to be transmitted, as in a table 1600 of FIG.16, for example. The QoS classes of the EPS bearers are identified byQoS class identifiers (QCIs).

The QCIs are classified into four ACs, i.e. voice (VO), video (VI), besteffort (BE), and background (BK). The WLAN receiver (e.g., the UE 311)performs conversion from ACs to the QoS classes. To that end, the eNB321 configures, in advance, EPS bearers to be transferred to the UE 311.On the contrary, in the downlink, for example, the UE 311 can specify anEPS bearer on the basis of the EPS bearer configured by the eNB 321. Inthe uplink, the UE 311 can perform the AC classification on the basis ofthe EPS bearer configured by the eNB 321.

FIG. 17 is a flowchart depicting an example of processing by atransmitter apparatus in the wireless communications system according tothe second embodiment. In FIG. 17, a downlink case will be describedwhere user data is transmitted from the eNB 321 to the UE 311.

First, the eNB 321 determines whether to execute aggregation using LTE-Aand a WLAN concurrently with respect to user data to the UE 311 (stepS1701). A method of the determination at step S1701 will be describedlater.

At step S1701, in a case of determining that aggregation is not to beexecuted (step S1701: NO), the eNB 321 transmits the user data destinedto the UE 311 by LTE-A (step S1702), and ends a series of operations. Atstep S1702, PDCP ciphering and header compression, etc. is performed forthe user data and subsequently the user data is transmitted. Incontrast, the UE 311 performs processing such as decoding for theciphering and header decompression for the header compression at thePDCP layer whereby the user data transmitted from the eNB 321 can bereceived.

At step S1701, in a case of determining that aggregation is to beexecuted (step S1701: YES), the eNB 321 configures an outer IP layer forperforming processing of the data to be transferred to the WLAN (stepS1703). As step S1703, the eNB 321 may control the UE 311 to configurean outer IP layer of the UE 311 matching that of the eNB 321.

Next, the eNB 321 concurrently uses LTE-A and WLAN and transmits theuser data to the UE 311 (step S1704), and ends a series of operations.At step S1704, the eNB 321 adds the outer IP header to the user data bythe outer IP layer configured at step S1703 and thereby transmits bytunneling, the user data to be transmitted by the WLAN.

At step S1704, in a case where the eNB 321 has the WLAN communicationfunction, the eNB 321 transmits the user data to the UE 311 by the LTE-Acommunication and WLAN communication functions thereof. On the otherhand, in a case where the eNB 321 does not have the WLAN communicationfunction, for user data that is to be transmitted by the WLAN, the eNB321 transfers the user data destined for the UE 311 to the secondary eNB323 that is connected with the eNB 321 and has the WLAN communicationfunction.

Since data transferred to the WLAN by the outer IP layer configured atstep S1703 has an outer IP header, in the WLAN, QoS control based on theToS field included in the outer IP header becomes possible.

The determination at step S1701, for example, can be performed based onwhether aggregation for the user data of the UE 311 has been instructedfrom the UE 311 or the network side (e.g., the PGW 332). Alternatively,the determination at step S1701, for example, can be performed based onwhether the amount of the user data to the UE 311 exceeds a threshold.The amount of the user data may be the amount per time, a total amountof a series of the user data of the UE 311, etc. Alternatively, thedetermination at step S1701, for example, can be performed based on adelay time of communication between the eNB 321 and the UE 311 by LTE-A,a delay period of communication between the eNB 321 and the UE 311 bythe WLAN, etc.

In FIG. 17, in a case where aggregation is not performed, an instance isdescribed in which only LTE-A is used to transmit user data. However, ina case where the eNB 321 does not perform aggregation, only the WLAN maybe used to transmit user data. In a case where aggregation is notperformed, determination of whether LTE-A or the WLAN is to be used, forexample, can be performed based on an instruction from the UE 311 or thenetwork side (e.g., the PGW 332). Alternatively, the determination, forexample, can be performed based on whether the amount of user data tothe UE 311 has exceeded a threshold. The amount of user data may be theamount per time, or the total amount of a series of user data of the UE311. Alternatively, the determination, for example, can be performedbased on a delay time of communication by LTE-A between the eNB 321 andthe UE 311, or a delay time of communication by the WLAN between the eNB321 and the UE 311.

In FIG. 17, although processing by the eNB 321 in a case of downlinktransmitting user data from the eNB 321 to the UE 311 is described,processing by the UE 311 in a case of uplink transmitting user data fromthe UE 311 to the eNB 321 is the same. However, the operation at stepS1704 differs depending on whether the eNB 321 has a WLAN communicationfunction. In a case in which the eNB 321 has a WLAN communication, theUE 311 directly transmits to the eNB 321, user data destined for the eNB321 and to be transmitted by the WLAN. On the other hand, in a case inwhich the eNB 321 does not have a WLAN communication, the UE 311transfers user data destined for the eNB 321 and to be transmitted bythe WLAN, to the secondary eNB 323 connected to the eNB 321 and having aWLAN communication function. As a result, user data destined for the eNB321 can be transmitted via the secondary eNB 323.

FIG. 18 is a diagram depicting an example of a case where plural EPSbearers have the same QoS class in the wireless communications systemaccording to the second embodiment. In FIG. 18, parts similar to thosedepicted in FIG. 14 are designated by the same reference numerals usedin FIG. 14 and explanations of similar parts will be omitted. Forexample, when both the IP packets 1401, 1402 are background IP packets,the IP packets 1401, 1402 are both classified into the AC 1314(background) in the ToS value analysis classification 1410.

In this case, the IP packet 1401 of HTTP is managed as IP flow ID=AC=3,bearer ID=0 in the mapping management 1320 in RRC between the UE 311 andthe eNB 321. In the mapping management 1320, the IP packet 1402 of FTPis managed as IP flow ID=AC=3, bearer ID=1.

In this case, even though the UE 311 performs the ToS value analysisclassification 1430 corresponding to the ToS value analysisclassification 1410, the UE 311 cannot determine based on AC which IPpacket 1401, 1402 received is which EPS bearer having bearer ID=0, 1.

In the case of transmitting user data through a WLAN, the LCID cannot beapplied to the IP datagram (PDCP SDU). For this reason, the eNB 321cannot determine based on LCID which IP packet 1401, 1402 received iswhich EPS bearer having bearer ID=0, 1.

In this manner, in the case that plural EPS bearers have the same QoSclass, the receiver (the UE 311 in the example depicted in FIG. 18) maynot be able to uniquely identify the EPS bearers. This means that thereceiver may not be able to convert the received radio bearers to EPSbearers. In the uplink in particular, IP flows between the eNB 321 andthe PGW 232 are managed as EPS bearers and hence, IP flow transmissionfrom the eNB 321 to the PGW 232 becomes difficult if the eNB 321 cannotconvert the radio bearers to EPS bearers.

On the contrary, in the wireless communications system 300 according tothe second embodiment, for example, the sender among the UE 311 and theeNB 321 does not concurrently perform aggregation for the EPS bearershaving the same QoS class.

For example, in a case of transmitting plural EPS bearers having thesame QoS class to the UE 311, the sender performs aggregation for onlyone of the plural EPS bearers to a WLAN and sends the remaining EPSbearers to the UE 211 by LTE-A without performing aggregation .Alternatively, in a case of transmitting plural EPS bearers having thesame QoS class to the UE 211, the sender performs transmission throughLTE-A without performing aggregation. As a result, plural EPS bearershaving the same QoS class are not concurrently transferred to a WLANwhereby the UE 211 can uniquely specify an EPS bearer on the basis ofthe AC, for each user data transferred to the WLAN.

Alternatively, in a case of sending plural bearers having the same QoSclass to the UE 311, the sender among the UE 311 and the eNB 321 mayperform a process of aggregating the plural EPS bearers into one bearer.The process of aggregating plural EPS bearers into one bearer can use“UE requested bearer resource modification procedure” defined inTS23.401 of 3GPP, for example. As a result plural EPS bearers having thesame QoS class are not transferred to the WLAN whereby the UE 211 canuniquely specify an EPS bearer on the basis of the AC, for each userdata transferred to a WLAN.

Further, for example, as described hereinafter (e.g., refer to FIGS. 22to 24), it is conceivable that the outer IP layer is acquired byseparately providing a new tunneling layer and by the tunneling layer, atunneling header that includes identification information for eachbearer is added to the data. In this case, regarding the user datatransferred to the WLAN, the UE 311 can use the identificationinformation to uniquely specify an EPS bearer.

FIG. 19 is a diagram depicting an example of implementation of the outerIP layer using a 3GPP protocol in the second embodiment. In the examplesdepicted in FIG. 15, etc., a case in which the outer IP layer isprovided as a part of the PDCP layer has been described. However, like aprotocol stack depicted in FIG. 19, an outer IP layer 1900 may beprovided as a lower layer of a PDCP layer 1901.

In this case, for example, the PDCP layer 1901 transfers to the outer IPlayer 1900, PDCP packets for which ciphering processing, etc. areperformed by the PDCP and to which a PDCP header is added, and IPheaders added to packets before the ciphering processing, etc. wereperformed by the PDCP. The PDCP header, for example, is a 2-byte header.

The outer IP layer 1900 adds, as an outer IP header to a PDCP packettransferred from a PDCP layer 1901, the IP header transferred from thePDCP layer 1901. As a result, PDCP packet can be transmitted through theWLAN by tunneling. The outer IP header, for example, is a 20-byte headerlike the inner IP header.

FIG. 20 is a diagram depicting another example of implementation of theouter IP layer using a 3GPP protocol in the second embodiment. In FIG.20, parts identical to those depicted in FIG. 19 are designated by thesame reference numerals used in FIG. 19 and explanations thereof will beomitted. Like a protocol stack depicted in FIG. 20, the outer IP layer1900 may be provided as a lower layer of a RLC layer 1902 and the PDCPlayer 1901.

In this case, for example, the PDCP layer 1901 transfers to the RLClayer 1902, PDCP packets for which ciphering processing, etc. areperformed by the PDCP and to which a PDCP header is added, and IPheaders (inner IP headers) added to packets before the cipheringprocessing, etc. were performed by the PDCP.

The RLC layer 1902 adds to PDCP packets transferred from the PDCP layer1901 an RLC header and transfers to the outer IP layer 1900, RLC packetsto which a RLC header has been added and the IP headers transferred fromthe PDCP layer 1901. The RLC header, for example, is a variable lengthheader.

The outer IP layer 1900 adds as an outer IP header to the RLC packetstransferred from the RLC layer 1902, the IP headers transferred from theRLC layer 1902. As a result, the RLC packets can be transmitted throughthe WLAN by tunneling. Therefore, retransmission control by, forexample, RLC becomes possible for data transferred by tunneling throughthe WLAN.

FIG. 21 is a diagram depicting another example of implementation of theouter IP layer using a 3GPP protocol in the second embodiment. In FIG.21, parts identical to those depicted in FIG. 20 are designated by thesame reference numerals used in FIG. 20 and explanations thereof will beomitted. Like a protocol stack depicted in FIG.21, the outer IP layer1900 may be provided as a lower layer of a MAC layer 1903, the RLC layer1902, and the PDCP layer 1901.

In this case, the RLC layer 1902 transfers to the MAC layer 1903, RLCpackets to which an RLC header is added, and IP headers transferred fromthe PDCP layer 1901. The MAC layer 1903 adds a MAC header to the PDCPpackets transferred from the RLC layer 1902 and transfers to the outerIP layer 1900, MAC frames to which a MAC header has been added and theIP headers transferred from the RLC layer 1902. The MAC header, forexample, is a variable length header.

The outer IP layer 1900 adds as an outer IP header to the MAC framestransferred from the MAC layer 1903, the IP headers transferred from theMAC layer 1903. As a result, the MAC frames can be transmitted throughthe WLAN by tunneling. Therefore, retransmission control by, forexample, HARQ tunneling becomes possible for data transferred bytunneling through the WLAN.

FIG. 22 is a diagram depicting an example of implementation of the outerIP layer using a new tunnel protocol in the second embodiment. In FIG.22, parts identical to those depicted in FIG. 19 are designated by thesame reference numerals used in FIG. 19 and explanations thereof will beomitted. As depicted in FIG. 22, a tunneling layer 2201 (TUN), which isa new tunneling protocol, may be provided between the PDCP layer 1901and the outer IP layer 1900.

The tunneling layer 2201 adds a tunneling header to PDCP packets towhich a PDCP header has been added by the PDCP layer 1901. Further, forexample, the tunneling layer 2201 may add to the PDCP packets, atunneling header that includes bearer identification information. Theouter IP layer 1900 adds an outer IP header to the packets to which atunneling header has been added by the tunneling layer 2201. The beareridentification information, for example, is a bearer ID. The receiverstation refers to the bearer ID whereby the receiver station can specifythe EPS bearer.

FIG. 23 is a diagram depicting another example of implementation of theouter IP layer using a new tunnel protocol in the second embodiment. InFIG. 23, parts identical to those depicted in FIG. 20 or FIG. 22 aredesignated by the same reference numerals used in FIG. 20 and FIG. 22,and explanations thereof will be omitted. As depicted in FIG. 23, thetunneling layer 2201 maybe provided between the RLC layer 1902 and theouter IP layer 1900. The tunneling layer 2201 adds a tunneling header toRLC packets to which an RLC header has been added by the RLC layer 1902.

FIG. 24 is a diagram depicting an example of implementation of the outerIP layer using a new tunnel protocol in the second embodiment. In FIG.24, parts identical to those depicted in FIG. 21 or FIG. 23 aredesignated by the same reference numerals used in FIG. 21 and FIG. 23,and explanations thereof will be omitted. As depicted in FIG. 24, thetunneling layer 2201 may be provided between the MAC layer 1903 and theouter IP layer 1900. The tunneling layer 2201 adds a tunneling header toMAC frames to which a MAC header has been added by the MAC layer 1903.

As depicted in FIGS. 19 to 24, the position where the outer IP layer1900 is provided is not limited to the PDCP layer 1901 and, for example,can be positions lower than the PDCP layer 1901. Further, for example,although a case has been described in which the outer IP layer 1900 isprovided separately from the RLC layer 1902 and the MAC layer 1903, apart of the RLC layer 1902 or the MAC layer 1903 may be provided as theouter IP layer 1900.

In this manner, according to the second embodiment, in a case where thetransmitting station among the eNB 321 and the UE 311 performsaggregation concurrently using LTE-A and a WLAN, PDCP packets to betransmitted by the WLAN can be transmitted by tunneling by the outer IP.As a result, at the receiving station, the data transmitted through theWLAN are received as PDCP packets and the PDCP sequence numbers can beused to perform sequence control between the packets received by LTE-Aand the packets received by the WLAN. Therefore, data transmission thatconcurrently uses LTE-A and a WLAN becomes possible.

Data transmission that concurrently uses LTE-A and a WLAN becomespossible whereby the transmission rate of data can be improved. Forexample, the maximum transmission rate in a case in which only one ofLTE-A and a WLAN is used is the maximum transmission rate for LTE-A whenLTE-A is used and is the maximum transmission rate for a WLAN when theWLAN is used. In contrast, the maximum transmission rate in a case inwhich LTE-A and a WLAN are used concurrently is a sum of the maximumtransmission rate for LTE-A and the maximum transmission rate for theWLAN.

Further, the transmitting station among the eNB 321 and the UE 311 canperform tunneling by adding to PDCP packets transmitted by the WLAN, anouter IP header that is a copy of the inner IP header. As a result, inthe WLAN, the ToS field included in the outer IP header of the IPpackets can be referred to. Therefore, for data transmitted by the WLAN,AC classification based on the ToS field can be performed and QoScontrol can be performed according to the nature of the traffic.

In a third embodiment, a method will be described that is capable ofincreasing the amount of user data that can be aggregated, byeliminating the restriction that EPS bearers having the same QoS classare not aggregated at the same time. The third embodiment can beregarded as an example obtained by embodying the above first embodimentand hence, can naturally be carried out in combination with the firstembodiment. The third embodiment can naturally be carried out incombination with parts common to the second embodiment.

FIG. 25 is a diagram depicting an example of a method of identifying EPSbearers using UL TFT in a wireless communications system according tothe third embodiment. In FIG. 25, parts similar to those depicted inFIG. 15 are designated by the same reference numerals used in FIG. 15and will not again be described.

In FIG. 25, the uplink will be described for a case of performingaggregation using LTE-A and a WLAN concurrently in a configuration wherethe eNB 321 has a WLAN communication function (eNB+WLAN). In the exampledepicted in FIG. 25, EPS bearers 1500 to 150 n are uplink directionbearers from the UE 311 to the eNB 321. In other words, the source (srcIP) of all the EPS bearers 1500 to 150 n is the UE 311 (UE). Thedestination (dst IP) of all the EPS bearers 1500 to 150 n is the corenetwork (CN).

The UE 311, in a case of performing aggregation using LTE-A and a WLANconcurrently for the EPS bearers 1500 to 150 n, passes the EPS bearers1500 to 150 n through the PDCP layers 1570 to 157 n. At this time, theUE 311 performs PDCP packet tunneling by adding an outer IP header toPDCP packets transmitted by the WLAN. As a result, the PDCP packetstransmitted by the WLAN become IP packets.

The UE 311 performs for the IP packets corresponding to EPS bearers 1500to 150 n going through the PDCP layers 1570 to 157 n, AC classification2510 based on the ToS field included the outer IP header of each IPpacket. The AC classification 2510 is processing by a WLAN function(802.11e) at the UE 311.

The IP packets classified by the AC classification 2510 are transmittedvia the WLAN 1550 to the eNB 321. The eNB 321 performs for the IPpackets received via the WLAN 1550, AC declassification 2520 based onthe ToS field included in the IP header of each IP packet. The ACdeclassification 2520 is processing by a WLAN function (802.11e) at theeNB 321.

Further, for packets transmitted by LTE-A in the respective EPS bearers1500 to 150 n, the UE 311 sequentially performs processing for RLC, MAC,and PHY wirelessly transmits the packets by LTE-A to the eNB 321 withoutadding an outer IP header. The eNB 321 performs processing by PHY, MAC,RLC, PDCP (the PDCP layers 1570 to 157 n) and thereby receives thepackets transmitted from the UE 311 by LTE-A.

The eNB 321 applies packet filtering 2530 based on uplink (UL) TFT, toeach of the IP packets received through the AC declassification 2520. Inthe packet filtering 2530, the IP packets are filtered depending onwhether conditions (f1to f3) corresponding to TFT are fulfilled(match/no). Then, in accordance with the results of this filtering, EPSbearer classification 2531 identifying the EPS bearers is carried out.As a result, EPS bearers corresponding to the IP packets transferred tothe WLAN are identified. A method of acquiring the UL TFT at the eNB 321will be described later (e.g., refer to FIG. 27).

On the basis of the results of identification by the EPS bearerclassification 2531, the eNB 321 transfers the IP packets to PDCP layerscorresponding to EPS bearers of the IP packets among the PDCP layers1510 to 151 n. Thus, the IP packets (IP flow) transferred to the WLANare converted into corresponding EPS bearers and transferred to the PDCPlayers 1510 to 151 n.

The eNB 321 acquires PDCP packets by removing the outer IP header addedto the IP packets received by the WLAN. The eNB 321 performs sequencecontrol between the PDCP packets received by the WLAN and the PDCPpackets received by LTE-A, based on the sequence numbers included in theheaders of the PDCP packets. As a result, the eNB 321 correctlyarranges, in sequence, the PDCP packets received by the WLAN and thePDCP packets received by LTE-A and thus, the eNB 321 can receive datathat has been divided between and transmitted by LTE-A and a WLAN.

In this manner, the eNB 321 performs the packet filtering 2530 based onUL TFT with respect to the IP packets transferred to the WLAN and isthereby able to identify the EPS bearers of the IP packets transferredto the WLAN. Therefore, the wireless communications system 300 makesaggregation possible even without a restriction that multiple RPSbearers having the same QoS class are not to be aggregated at the sametime and the wireless communications system 300 can facilitate increasesin the amount of user data that can be transmitted.

FIG. 26 is a diagram depicting another example of a method ofidentifying EPS bearers using UL TFT in the wireless communicationssystem according to the third embodiment. In FIG. 26, parts similar tothose depicted in FIG. 15 or 25 are designated by the same referencenumerals and explanations thereof will be omitted.

In FIG. 26, a case of the uplink will be described where aggregation isperformed concurrently using LTE-A and a WLAN in the WLAN standaloneconfiguration using the secondary eNB 323 having the eNB and WLANcommunication functions, with the eNB 321 serving as a master eNB. Inthis case, the GTP tunnels 1520 to 152 n are provided for each of theEPS bearers between the eNB 321 and the secondary eNB 323.

The secondary eNB 323 receives the IP packets transmitted via the WLAN1550 from the UE 311. The secondary eNB 323 performs the ACdeclassification 2520 and the packet filtering 2530 similar to those inthe example depicted in FIG. 25, for each of the received IP packets.This allows the EPS bearer classification 2531 in the packet filtering2530 to be performed for each IP packet so that an EPS bearercorresponding to each IP packet is identified.

Based on the result of identification by the EPS bearer classification2531, the secondary eNB 323 transfers each IP packet to a GTP tunnelcorresponding to the EPS bearer of the each IP packet, among the GTPtunnels 1520 to 152 n. As a result, the IP packets are transferred tocorresponding PDCP layers among the PDCP layers 1510 to 151 n of the eNB321.

In this manner, the secondary eNB 323 performs the packet filtering 2530based on UL TFT for the IP packets transferred to the WLAN, so as to beable to identify the EPS bearers of the IP packets transferred to theWLAN. Depending on the results of identification of the EPS bearers, thesecondary eNB 323 then transfers the IP packets through the GTP tunnels1520 to 152 n, whereby the eNB 321 can receive the IP packetstransferred to the WLAN, as EPS bearers.

Thus, without configuring the restriction that EPS bearers having thesame QoS class are not to be aggregated at the same time, the wirelesscommunications system 300 makes aggregation possible and can facilitatean increase in the amount of user data that can be transferred.

FIG. 27 is a diagram depicting an example of a TFT acquisition method inthe wireless communications system according to the third embodiment.Steps depicted in FIG. 27 are processes of a “Dedicated beareractivation procedure” defined in TS23.401 of 3GPP. A policy and chargingrules function (PCRF) 2001 depicted in FIG. 27 is a processing unit forconfiguring service-dependent priority control and charging rules,connected to the packet core network 330.

For example, the PGW 332 configures UL and DL TFTs for the UE 311,stores the TFTs to a create bearer request 2702 depicted in FIG. 27, andtransmits the create bearer request 2702 to the SGW 331. The SGW 331transmits the create bearer request 2702 sent from the PGW 332, to theMME 333.

The MME 333 transmits to the eNB 321, a bearer setup request/sessionmanagement request 2703 including the TFTs included in the create bearerrequest 2702 transmitted from the SGW 331. The TFTs are included in asession management request of the bearer setup request/sessionmanagement request 2703, for example. This enables the eNB 321 toacquire the UL and DL TFTs.

The eNB 321 transmits to the UE 311, an RRC connection reconfiguration2704 including a UL TFT among the TFTs included in the bearer setuprequest/session management request 2703 transmitted from the MME 333.This enables the UE 311 to acquire the UL TFT. Although the UL TFT canbe defined in an RRC connection reconfiguration message, it ispreferably defined in a non-access stratum (NAS) PDU transmitted in themessage. The same will apply hereinafter.

In the example depicted in FIG. 25, for example, the eNB 321 can performthe packet filtering 2530 using the UL TFT acquired from the bearersetup request/session management request 2703. In the example depictedin FIG. 26, the eNB 321 transmits the UL TFT acquired from the bearersetup request/session management request 2703, to the secondary eNB 323.The secondary eNB 323 can perform the packet filtering 2530 on the basisof the UL TFT sent from the eNB 321.

FIG. 28 is a diagram depicting an example of a method of identifying EPSbearers using DL TFT in the wireless communications system according tothe third embodiment. In FIG. 28, parts similar to those depicted inFIG. 15 are designated by the same reference numerals used in FIG. 15and explanations thereof will be omitted.

In FIG. 28, a downlink case will be described where aggregation isperformed concurrently using LTE-A and a WLAN in a configuration inwhich the eNB 321 has a WLAN communication function (eNB+WLAN). In theexample depicted in FIG. 28, the EPS bearers 1500 to 150 n are downlinkdirection bearers from the eNB 321 to the UE 311.

The UE 311 performs a packet filtering 2810 based on downlink (DL) TFTs,for IP packets received by the AC declassification 1560. The packetfiltering 2810 by the UE 311 is processing based on the DL TFTs andtherefore, is processing similar to the packet filtering by the filterlayer 811 in the PGW 332 depicted in FIG. 8, for example.

In the packet filtering 2810, filtering is performed depending onwhether (match/no) the IP packets satisfy conditions (f1 to f3)corresponding to TFTs. An EPS bearer classification 2811 identifying EPSbearers is carried out according to the results of this filtering. Thisallows identification of EPS bearers corresponding to the IP packetstransferred to the WLAN.

For example, the eNB 321 stores not only the UL TFTs but also DL TFTsinto the RRC connection reconfiguration 2704 destined for the UE 311,depicted in FIG. 27. This enables the UE 311 to acquire a DL TFT fromthe RRC connection reconfiguration 2704, to thereby perform the packetfiltering 2810 based on the acquired DL TFT.

Based on the results of identification by the EPS bearer classification2811, the UE 311 transfers the IP packets to PDCP layers correspondingto the EPS bearers of the IP packets, among the PDCP layers 1570 to 157n. As a result, the IP packets (IP flow) transferred to the WLAN areconverted into corresponding EPS bearers and transferred to the PDCPlayers 1570 to 157 n.

In this manner, by applying the packet filtering 2810 based on a DL TFTto the IP packets transferred to the WLAN, the UE 311 can identify EPSbearers of the IP packets transferred to the WLAN. Thus, withoutconfiguring the restriction that EPS bearers having the same QoS classare not to be aggregated at the same time, the wireless communicationssystem 300 makes aggregation possible and can facilitate an increase inthe amount of user data that can be transferred.

FIG. 29 is a diagram depicting another example of a method ofidentifying EPS bearers using DL TFTs in the wireless communicationssystem according to the third embodiment. In FIG. 29, parts similar tothose depicted in FIG. 15 or 28 are designated by the same referencenumerals used in FIGS. 15 and 28 and explanations thereof will beomitted.

In FIG. 29, a downlink case will be described where aggregation isperformed concurrently using LTE-A and a WLAN in the WLAN standaloneconfiguration using the secondary eNB 323 having eNB and WLANcommunication functions, with the eNB 321 serving as a master eNB. Inthis case, the GTP tunnels 1520 to 152 n are provided for each of theEPS bearers between the eNB 321 and the secondary eNB 323.

The secondary eNB 323 receives the IP packets transmitted via the WLAN1550 from the UE 311. The secondary eNB 323 then transfers the receivedIP packets to the PDCP layers 1570 to 157 n.

Thus, similar to the example depicted in FIG. 28, the UE 311 performsthe packet filtering 2810 based on a DL TFT for the IP packetstransferred to the WLAN, so as to be able to identify the EPS bearers ofthe IP packets transferred to the WLAN. Thus, without configuring therestriction that EPS bearers having the same QoS class are not to beaggregated at the same time, the wireless communications system 300makes aggregation possible and can facilitate an increase in the amountof user data that can be transferred.

According to the method using the TFTs depicted in FIGS. 25 to 29, theEPS bearers can be identified without the number of EPS bearerstransferrable to the WLAN being restricted by the bit number of the VLANtag, as in the case of using the VLAN tag, for example. According to themethod using the TFTs depicted in FIGS. 25 to 29, the EPS bearers can beidentified without adding a header such as the VLAN tag to the user datatransferred to the WLAN.

FIG. 30 is a diagram depicting an example of a method of identifying EPSbearers using a virtual IP flow in the wireless communications systemaccording to the third embodiment. In FIG. 30, parts similar to thosedepicted in FIG. 15 are designated by the same reference numerals usedin FIG. 15 and explanations thereof will be omitted.

In FIG. 30, regarding downlink, a case will be described whereaggregation is performed concurrently using LTE-A and a WLAN in aconfiguration in which the eNB 321 has a WLAN communication function(eNB+WLAN). In the example depicted in FIG. 30, the EPS bearers 1500 to150 n are downlink direction bearers from the eNB 321 to the UE 311.

In the example depicted in FIG. 30, a virtual GW 3010 is providedbetween the PDCP layers 1510 to 151 n and the WLAN 1550 in the eNB 321.The virtual GW 3010 includes NAT processing units 3020 to 302 n and aMAC processing unit 3030 (802.3 MAC). A virtual GW 3040 is providedbetween the WLAN 1550 and the PDCP layers 1570 to 157 n in the UE 311.The virtual GW 3040 includes a MAC processing unit 3050 (802.3 MAC) andde-NAT processing units 3060 to 306 n.

The EPS bearers 1500 to 150 n passing through the PDCP layers 1510 to151 n are transferred to the NAT processing units 3020 to 302 n of thevirtual GW 3010. The NAT processing units 3020 to 302 n perform networkaddress translation (NAT) processes that classify the EPS bearers 1500to 150 n, respectively, by virtual destination IP addresses into virtualIP flows. The virtual IP flow is a local virtual data flow between theeNB 321 and the UE 311 for example. The virtual destination IP addressis a destination address of the virtual IP flow. The NAT processingunits 3020 to 302 n transfer the classified IP flows to the MACprocessing unit 3030.

For example, the NAT processing units 3020 to 302 n perform one-to-onemapping between the EPS bearers 1500 to 150 n and the virtualdestination IP addresses. Virtual source IP addresses (src IP) of thevirtual IP flows transferred from the NAT processing units 3020 to 302 ncan be a virtual GW 3010 (vGW) for example. Virtual destination IPaddresses (dst IP) of the virtual IP flows transferred from the NATprocessing units 3020 to 302 n can be C-RNTI+0 to C-RNTI+n,respectively, for example.

Although the virtual destination IP addresses, for example, can becalculated from C-RNTI, the virtual destination IP addresses are notlimited hereto. For example, at the time of call configuration orLTE-WLAN aggregation configuration, EPS bearer identifiers and IPaddresses may be associated in advance by RRC signaling by the eNB 321(the master eNB) and notified to the UE 311 (mobile station).

A cell-radio network temporary identifier (C-RNTI) is temporarilyallocated to the UE 311 and is a unique identifier of the UE 311 withinan LTE-A cell. For example, C-RNTI has a 16-bit value. As in the exampledepicted in FIG. 30, C-RNTI and the bearer identifiers (0 to n) areadded together to generate virtual source IP addresses, whereby thevirtual source IP addresses can be prevented from occurring induplicate. For example, in the case of using class A IP addresses, EPSbearers of about 24 bits can be identified, sufficient for transmissionby the WLAN. Although a case has been described herein of adding C-RNTIand bearer identifiers together to generate virtual source IP addresses,the method of generating the virtual source IP addresses is not limitedhereto.

The MAC processing unit 3030 converts virtual IP flows transferred fromthe NAT processing units 3020 to 302 n, into MAC frames of Ethernet,IEEE 802.3, etc. In this case, the source MAC addresses (src MAC) of MACframes may be, for example, any private addresses in the virtual GWs3010, 3040. For example, the MAC-frame source MAC addresses can beaddresses with top octet of “xxxxxx10” (x represents an arbitraryvalue). Destination MAC addresses (dst MAC) of MAC frames can be MACaddresses (UE MAC) of the UE 311, for example.

The eNB 321 performs the AC classification 1540 for MAC frames convertedby the MAC processing unit 3030 and transmits the MAC frames for whichthe AC classification 1540 has been performed, to the UE 311 via theWLAN 1550.

The UE 311 applies the AC declassification 1560 to the MAC framesreceived from the eNB 321 via the WLAN 1550. The MAC processing unit3050 of the virtual GW 3040 receives the MAC frames for which the ACdeclassification 1560 has been performed, as virtual IP flows.

The de-NAT processing units 3060 to 306 n convert the virtual IP flowsreceived by the MAC processing unit 3050 into EPS bearers, by referringto virtual destination IP addresses (dst IP) of the virtual IP flows. Atthis time, the virtual destination IP addresses of the virtual IP flowsare converted into the original IP addresses by de-NAT by the de-NATprocessing units 3060 to 306 n.

In this manner, by providing the virtual GWs 3010 and 3040 in the eNB321 and the UE 311, respectively, and by utilizing NAT, the EPS bearerscan be identified as virtual IP flows at the virtual GWs 3010, 3040. TheIP addresses and the MAC addresses can be in the form of private spaceaddresses. By building a virtual IP network between the virtual GWs 3010and 3040 in this manner, EPS bearers of the IP packets transferred tothe WLAN can be identified. Thus, without configuring the restrictionthat EPS bearers having the same QoS class are not to be aggregated atthe same time, the wireless communications system 300 makes aggregationpossible and can facilitate an increase in the amount of user data thatcan be transferred.

Although the downlink has been described in FIG. 30, a similar method isapplicable to the uplink, for the identification of EPS bearers. Thatis, by building a virtual IP network between the virtual GWs 3010 and3040 configured in the eNB 321 and UE 311, EPS bearers of IP packetstransferred to the WLAN can be identified in the uplink.

FIG. 31 is a diagram depicting another example of a method ofidentifying EPS bearers using virtual IP flow in the wirelesscommunications system according to the third embodiment. In FIG. 31,parts similar to those depicted in FIG. 15 or 30 are designated by thesame reference numerals used in FIGS. 15 and 30 and explanations thereofwill be omitted.

In FIG. 31, regarding downlink, a case will be described whereaggregation is performed concurrently using LTE-A and a WLAN in the WLANstandalone configuration using the secondary eNB 323 having eNB and WLANcommunication functions, with the eNB 321 serving as a master eNB. Inthis case, the GTP tunnels 1520 to 152 n are provided for each of theEPS bearers between the eNB 321 and the secondary eNB 323.

The NAT processing units 3020 to 302 n depicted in FIG. 30 areestablished in the secondary eNB 323 in an example depicted in FIG. 31.The secondary eNB 323 receives IP packets transmitted from the UE 311via the WLAN 1550. The secondary eNB 323 transfers the received IPpackets to the NAT processing units 3020 to 302 n of the virtual GW3010.

Similar to the example depicted in FIG. 30, this enables the EPS bearersto be identified as virtual IP flows in the virtual GWs 3010, 3040.Thus, without configureing the restriction that EPS bearers having thesame QoS class are not to be aggregated at the same time, the wirelesscommunications system 300 makes aggregation possible and can facilitatean increase in the amount of user data that can be transferred.

Although the downlink has been described in FIG. 31, a similar method isapplicable to the uplink, for identification of EPS bearers. That is, bybuilding a virtual IP network between the virtual GWs 3010 and 3040configured in the eNB 321 and UE 311, EPS bearers of IP packetstransferred to the WLAN can be identified in the uplink.

According to the method using the virtual IP flows depicted in FIGS. 30and 31, the EPS bearers may be identified without the number of EPSbearers transferrable to the WLAN being restricted by the bit number ofthe VLAN tag, as in the case of using the VLAN tag, for example.According to the method using the virtual IP flows depicted in FIGS. 30and 31, connection between the eNB 321 and the secondary eNB 323 ispossible by Ethernet, etc. and is not limited to the GTP tunnels.

According to the method using the virtual IP flows depicted in FIGS. 30and 31, the EPS bearers can be identified without configuring a DL TFTin the UE 311 and without configuring a UL TFT in the eNB 321. Accordingto the method using the virtual IP flows depicted in FIGS. 30 and 31,the EPS bearers can be identified without adding a header such as theVLAN tag to the user data transferred to the WLAN.

FIG. 32 is a diagram depicting an example of a method of identifying EPSbearers using VLAN in the wireless communications system according tothe third embodiment. In FIG. 32, parts similar to those depicted inFIG. 15 or 30 are designated by the same reference numerals used inFIGS. 15 and 30 and explanations thereof will be omitted. Although themethod of identifying EPS bearers by building the virtual IP network hasbeen described in FIG. 30, a method of identifying EPS bearers by VLANvirtualizing Ethernet will be described in FIG. 32.

In FIG. 32, regarding downlink, a case will be described whereaggregation is performed concurrently using LTE-A and a WLAN in aconfiguration in which the eNB 321 has a WLAN communication function(eNB+WLAN). In this case, the EPS bearers 1500 to 150 n are downlinkdirection bearers from the eNB 321 to the UE 311.

In the example depicted in FIG. 32, similar to the example depicted inFIG. 30, the virtual GWs 3010 and 3040 are established in the eNB 321and the UE 311, respectively. It is to be noted that in the exampledepicted in FIG. 32, the virtual GW 3010 of the eNB 321 includes VLANprocessing units 3210 to 321 n and MAC processing units 3220 to 322 n(802.3 MAC). The virtual GW 3040 of the UE 311 includes MAC processingunits 3230 to 323 n (802.3 MAC) and de-VLAN processing units 3240 to 324n.

The EPS bearers 1500 to 150 n passing through the PDCP layers 1510 to151 n are transferred to the VLAN processing units 3210 to 321 n of thevirtual GW 3010. The VLAN processing units 3210 to 321 n classify theEPS bearers 1500 to 150 n, respectively, by VLAN into local IP flowsbetween the eNB 321 and the UE 311, and transfer the classified IP flowsto the MAC processing units 3220 to 322 n.

For example, the VLAN processing units 3210 to 321 n perform one-to-onemapping between the EPS bearers 1500 to 150 n and the VLAN tags. VLANidentifiers of the IP flows transferred from the VLAN processing units3210 to 321 n can be 0 to n, respectively.

The MAC processing units 3220 to 322 n convert the IP flows transferredfrom the VLAN processing units 3210 to 321 n, respectively, into MACframes of Ethernet, IEEE 802.3, etc. The source MAC addresses (src MAC)of MAC frames converted by the MAC processing units 3220 to 322 n canbe, for example, any private addresses in the virtual GWs 3010, 3040.For example, the MAC-frame source MAC addresses can be addresses withtop octet of “xxxxxx10” (x represents an arbitrary value). Thedestination MAC addresses (dst MAC) of MAC frames converted by the MACprocessing units 3220 to 322 n can be MAC addresses (UE MAC) of the UE311, for example.

The VLAN tags of MAC frames converted by the MAC processing units 3220to 322 n can be, for example, 0 to n corresponding to the respective EPSbearers. In this manner, a VLAN tag for each EPS bearer is applied toeach of the MAC frames. The VLAN tag is a 12-bit tag, for example. Thus,a maximum of 4094 VLANs can be built between the virtual GWs 2210 and3040. Assuming that the UEs including the UE 311 provide all the EPSbearers and that all the EPS bearers are transferred to the WLAN, about472 UEs can be accommodated in the WLAN. Note that since the actualpossibility that communication using all the EPS bearers is low, use ofVLAN enables a sufficient number of EPS bearers to be transferred to theWLAN.

The eNB 321 performs the AC classification 1540 for MAC frames with VLANtags converted by the MAC processing units 3220 to 322 n. The eNB 321transmits the MAC frames with VLAN tags for which the AC classification1540 has been performed, to the UE 311 via the WLAN 1550.

The UE 311 applies the AC declassification 1560 to the MAC frames withVLAN tags received via the WLAN 1550 from the eNB 321. The MACprocessing units 3230 to 323 n of the virtual GW 3040 are MAC processingunits corresponding to the EPS bearers 1500 to 150 n, respectively. Eachof the MAC processing units 3230 to 323 n refers to the VLAN tag addedto the MAC frame for which the AC declassification 1560 has beenperformed, and thereby receives a MAC frame of a corresponding EPSbearer as an IP flow.

The de-VLAN processing units 3240 to 324 n convert the IP flows receivedby the MAC processing units 3230 to 323 n, respectively, into EPSbearers 1500 to 150 n. The PDCP layers 1570 to 157 n process the EPSbearers 1500 to 150 n converted by the de-VLAN processing units 3240 to324 n, respectively.

In this manner, by configuring the VLAN for each of the EPS bearersbetween the virtual GWs 3010 and 3040, EPS bearers of IP packetstransferred to the WLAN can be identified. Thus, without configuring therestriction that EPS bearers having the same QoS class are not to beaggregated at the same time, the wireless communications system 300makes aggregation possible and can facilitate an increase in the amountof user data that can be transferred.

Although the downlink has been described in FIG. 32, a similar method isapplicable to the uplink, for identification of EPS bearers. That is, byconfiguring the VLAN for each of the EPS bearers between the virtual GWs3010 and 3040 configured in the eNB 321 and the UE 311, EPS bearers ofIP packets transferred to the WLAN can be identified.

FIG. 33 is a diagram depicting another example of a method ofidentifying EPS bearers using VLAN in the wireless communications systemaccording to the third embodiment. In FIG. 33, parts similar to thosedepicted in FIG. 15 or 32 are designated by the same reference numeralsused in FIGS. 15 and 32 and explanations thereof will be omitted.

In FIG. 33, regarding downlink, a case will be described whereaggregation is performed concurrently using LTE-A and a WLAN in the WLANstandalone configuration using the secondary eNB 323 having eNB and WLANcommunication functions, with the eNB 321 serving as a master eNB. Inthis case, the GTP tunnels 1520 to 152 n are provided for each of theEPS bearers between the eNB 321 and the secondary eNB 323.

The VLAN processing units 3210 to 321 n depicted in FIG. 32 are equippedin the secondary eNB 323 in an example depicted in FIG. 33. Thesecondary eNB 323 receives IP packets transmitted from the UE 311 viathe WLAN 1550. The secondary eNB 323 then transfers the received IPpackets to the VLAN processing units 3210 to 321 n of the virtual GW3010.

Similar to the example depicted in FIG. 32, this makes it possible forthe EPS bearers to be identified as virtual IP flows in the virtual GWs3010, 3040. Thus, without configuring the restriction that EPS bearershaving the same QoS class are not to be aggregated at the same time, thewireless communications system 300 makes aggregation possible and canfacilitate an increase in the amount of user data that can betransferred.

Although the downlink has been described in FIG. 33, a similar method isapplicable to the uplink, for identification of EPS bearers. That is, byconfiguring a VLAN for each EPS bearer between the virtual GWs 3010 and3040 configured in the eNB 321 and UE 311, EPS bearers of IP packetstransferred to the WLAN can be identified.

According to the method using the VLAN depicted in FIGS. 32 and 33,connection between the eNB 321 and the secondary eNB 323 is possible byEthernet, etc. and is not limited to the GTP tunnels. According to themethod using the VLAN depicted in FIGS. 32 and 33, EPS bearers of IPpackets can be identified by adding the VLAN tag without packetprocessing referring to the IP header in WLAN. According to the methodusing the VLAN depicted in FIGS. 32 and 33, EPS bearers can beidentified without configuring the DL TFT in the UE 311 and withoutconfiguring the UL TFT in the eNB 321.

FIG. 34 is a diagram depicting an example of a method of identifying EPSbearers using GRE tunneling in the wireless communications systemaccording to the third embodiment. In FIG. 34, parts similar to thosedepicted in FIG. 15 or 30 are designated by the same reference numeralsused in FIGS. 15 and 30 and explanations thereof will be omitted.

In FIG. 34, regarding downlink, a case will be described whereaggregation is performed concurrently using LTE-A and a WLAN in aconfiguration in which the eNB 321 has a WLAN communication function(eNB+WLAN). In the example depicted in FIG. 34, the EPS bearers 1500 to150 n are downlink direction bearers from the eNB 321 to the UE 311.

In the example depicted in FIG. 34, the virtual GW 3010 is providedbetween the PDCP layers 1510 to 151 n and the WLAN 1550 in the eNB 321.The virtual GW 3010 includes GRE processing units 3410 to 341 n and theMAC processing unit 3030 (802.3 MAC). The virtual GW 3040 is providedbetween the WLAN 1550 and the PDCP layers 1570 to 157 n in the UE 311.The virtual GW 3040 includes the MAC processing unit 3050 (802.3 MAC)and de-GRE processing units 3420 to 342 n.

The EPS bearers 1500 to 150 n passing through the PDCP layers 1510 to151 n are transferred to the GRE processing units 3410 to 341 n of thevirtual GW 3010. The GRE processing units 3410 to 341 n classify each ofthe EPS bearers 1500 to 150 n, respectively, by applying generic routingencapsulation (GRE) tunneling to local IP flows between the eNB 321 andthe UE 311, and transfer the classified IP flows to the MAC processingunit 3030.

For example, the GRE processing units 3410 to 341 n add GRE headers andthen IP headers to IP packets corresponding to the EPS bearers 1500 to150 n and transfer the IP packets as IP flows to the MAC processing unit3030. The source IP addresses (src IP) of the IP flows transferred fromthe GRE processing units 3410 to 341 n can be the virtual GW (vGW) 3010,for example. The destination IP addresses (dst IP) of the IP flowstransferred from the GRE processing units 3410 to 341 n can be forexample C-RNTI+0 to C-RNTI+n, respectively.

Similar to the example depicted in FIG. 30 for example, the MACprocessing unit 3030 converts the IP flows transferred from the GREprocessing units 3410 to 341 n, into MAC frames of Ethernet (IEEE802.3).

The eNB 321 applies the AC classification 1540 to the MAC framesconverted by the MAC processing unit 3030 and transmits the MAC framesfor which the AC classification 1540 has been performed, to the UE 311via the WLAN 1550. As a result, the eNB 321 can transmit user datathrough a GRE tunnel (encapsulated tunnel) of the WLAN provided betweenthe eNB 321 and the UE 311.

The UE 311 applies the AC declassification 1560 to the MAC framesreceived from the eNB 321, via the WLAN 1550. Similar to the exampledepicted in FIG. 30 for example, the MAC processing unit 3050 of thevirtual GW 3040 receives, as IP flows, the MAC frames for which the ACdeclassification 1560 has been performed.

The de-GRE processing units 3420 to 342 n refer to destination IPaddresses (dst IP) included in IP headers of the IP flows received bythe MAC processing unit 3050 and thereby convert the IP flows into EPSbearers.

In this manner, by configuring the virtual GWs 3010 and 3040 in the eNB321 and the UE 311, respectively, and by utilizing the GRE tunneling,the EPS bearers can be identified as IP flows at the virtual GWs 3010,3040. The IP addresses and the MAC addresses can be in the form ofprivate space addresses. By building the GRE tunnel between the virtualGWs 3010 and 3040 in this manner, EPS bearers of the IP packetstransferred to the WLAN can be identified. Thus, without configuring therestriction that EPS bearers having the same QoS class are not to beaggregated at the same time, the wireless communications system 300makes aggregation possible and can facilitate an increase in the amountof user data that can be transferred.

Although the downlink has been described in FIG. 34, a similar method isapplicable to the uplink, for identification of EPS bearers. That is, bybuilding the GRE tunnel between the virtual GWs 3010 and 3040, EPSbearers of IP packets transferred to the WLAN can be identified.

FIG. 35 is a diagram depicting another example of a method ofidentifying EPS bearers using GRE tunneling in the wirelesscommunications system according to the third embodiment. In FIG. 35,parts similar to those depicted in FIG. 15 or 34 are designated by thesame reference numerals used in FIGS. 15 and 34 and explanations thereofwill be omitted.

In FIG. 35, regarding downlink, a case will be described whereaggregation is performed concurrently using LTE-A and a WLAN in the WLANstandalone configuration using the secondary eNB 323 having eNB and WLANcommunication functions, with the eNB 321 serving as a master eNB. Inthis case, the GTP tunnels 1520 to 152 n are provided for each of theEPS bearers between the eNB 321 and the secondary eNB 323.

The secondary eNB 323 receives IP packets transmitted from the UE 311via the WLAN 1550. The secondary eNB 323 transfers the received IPpackets to the GRE processing units 3410 to 341 n.

As a result, similar to the example depicted in FIG. 34, the UE 311 canidentify EPS bearers of the IP packets transferred to the WLAN byutilizing the GRE tunneling. Thus, without configuring the restrictionthat EPS bearers having the same QoS class are not to be aggregated atthe same time, the wireless communications system 300 makes aggregationpossible and can facilitate an increase in the amount of user data thatcan be transferred.

According to the method using the GRE tunneling depicted in FIGS. 34 and35, the EPS bearers can be identified without the number of EPS bearersfor transfer being restricted by the bit number of the VLAN tag, as inthe case of using the VLAN tag, for example. According to the methodusing the GRE tunneling depicted in FIGS. 34 and 35, connection betweenthe eNB 321 and the secondary eNB 323 is possible by Ethernet, etc. andis not limited to the GTP tunnels.

According to the method using GRE tunneling depicted in FIGS. 34 and 35,the EPS bearers can be identified without configuring a DL TFT in the UE311 and without configuring a UL TFT in the eNB 321. According to themethod using GRE tunneling depicted in FIGS. 34 and 35, the EPS bearerscan be identified without adding a header such as the VLAN tag to theuser data transferred to the WLAN.

FIG. 36 is a diagram depicting an example of a method of identifying anEPS bearer by using PDCPoIP in the wireless communications systemaccording to the third embodiment. In FIG. 36, parts identical to thosedepicted in FIG. 15 or FIG. 30 are designated by the same referencenumerals used in FIG. 15 and FIG. 30 and explanations thereof will beomitted.

In FIG. 36, regarding downlink, a case will be described in which theeNB 321 is configured to have a WLAN communications function (eNB+WLAN)and performs aggregation using LTE-A and WLAN concurrently. In theexample depicted in FIG. 36, the EPS bearers 1500 to 150 n are downlinkdirection bearers from the eNB 321 to the UE 311.

In the example depicted in FIG. 36, the virtual GW 3010 is configuredbetween the WLAN 1550 and the PDCP layers 1510 to 151 n in the eNB 321.The virtual GW 3010 includes PDCPoIP processing units 3610 to 361 n andthe MAC processing unit 3030 (802.3 MAC). Further, the virtual GW 3040is configured between the PDCP layers 1570 to 157 n and the WLAN 1550 inthe UE 311. The virtual GW 3040 includes the MAC processing unit 3050(802.3 MAC) and de-PDCPoIP processing units 3620 to 362 n (de-PoIP).

The EPS bearers 1500 to 150 n passing through the PDCP layers 1510 to151 n are transferred to the PDCPoIP processing units 3610 to 361 n ofthe virtual GW 3010. The PDCPoIP processing units 3610 to 361 n eachconverts the outer IP header addresses of the EPS bearers 1500 to 150 ninto a virtual IP address and thereby performs a PDCPoIP (Packet DataConvergence Protocol on IP) process of classification into virtual IPflows. A virtual IP flow, for example, is local virtual data flowbetween the eNB 321 and the UE 311. A virtual destination IP address isa destination address of a virtual IP flow. The PDCPoIP processing units3610 to 361 n transfer the classified virtual IP flows to the MACprocessing unit 3030.

For example, the PDCPoIP processing units 3610 to 361 n map the EPSbearers 1500 to 150 n and the virtual destination IP addresses on aone-to-one basis. The virtual source IP addresses (src IPs) of thevirtual IP flows transferred from the PDCPoIP processing units 3610 to361 n, for example, can be that of the virtual GW 3010 (vGW). Further,the virtual destination IP addresses (dst IP) of the virtual IP flowstransferred from the PDCPoIP processing units 3610 to 361 n, forexample, can be C-RNTI+0˜C-RNTI+n, respectively.

C-RNTI is a unique identifier of the UE 311 in the LTE-A cell and istemporarily allocated to the UE 311. For example, C-RNTI has a 16-bitvalue. As depicted in the example in FIG. 36, C-RNTI and beareridentifiers (0 to n) are added to generate virtual source IP addresseswhereby generation of overlapping virtual source IP addresses can beavoided. For example, when a class A IP address is used, EPS bearers forabout 24 bits sufficient for transmission by WLAN can be identified.Here, although a case is described in which C-RNTI and a beareridentifier are added to generate a virtual source IP address, the methodof generating the virtual source IP address is not limited hereto.

The MAC processing unit 3030 converts the virtual IP flows transferredfrom the PDCPoIP processing units 3610 to 361 n into MAC frames forEthernet, IEEE 802.3, etc. In this case, the source MAC address (srcMAC) of the MAC frame, for example, can be an arbitrary address (anyprivate address) in the virtual GWs 3010, 3040. For example, the sourceMAC address of the MAC frame can be an address starting with an octet of“xxxxxx10” (x is an arbitrary value). Further, a destination MAC address(dst MAC) of the MAC frame, for example, can be the MAC address (UE MAC)of the UE 311

The eNB 321 performs the AC classification 1540 for the MAC framesconverted by the MAC processing unit 3030 and transmits the MAC framesfor which the AC classification 1540 was performed to the UE 311, viathe WLAN 1550.

The UE 311 performs the AC declassification 1560 for the MAC framesreceived from the eNB 321, via the WLAN 1550. The MAC processing unit3050 of the virtual GW 3040 receives, as virtual IP flows, the MACframes for which the AC declassification 1560 was performed.

For the virtual IP flows received by the MAC processing unit 3050, thede-PDCPoIP processing units 3620 to 362 n convert the virtual IP flow inEPS bearers by referring to the virtual destination IP addresses (dstIP) of the virtual IP flows. At this time, virtual destination IPaddresses of the virtual IP flows are converted into the original IPaddresses by de-PDCPoIP by the de-PDCPoIP processing units 3620 to 362n.

In this manner, by providing the virtual GWs 3010 and 3040 in the eNB321 and the UE 3111, respectively, and by utilizing the addressconversion by PDCPoIP, the EPS bearers can be identified as virtual IPflows at the virtual GWs 3010, 3040. The IP addresses and the MACaddresses can be in the form of private space addresses. By building thea virtual IP network between the virtual GWs 3010 and 3040 in thismanner, EPS bearers of the IP packets transferred to the WLAN can beidentified. Thus, without configuring the restriction that EPS bearershaving the same QoS class are not to be aggregated at the same time, thewireless communications system 300 makes aggregation possible and canfacilitate an increase in the amount of user data that can betransferred.

Although the downlink has been described in FIG. 36, a similar method isapplicable to the uplink, for identification of EPS bearers. That is, bybuilding a virtual IP network between the virtual GWs 3010 and 3040configured in the eNB 321 and UE 311, EPS bearers of IP packetstransferred to the WLAN can be identified in the uplink.

FIG. 37 is a diagram depicting another example of a method ofidentifying EPS bearers using PDCPoIP in the wireless communicationssystem according to the third embodiment. In FIG. 37, parts identical tothose depicted in FIG. 15 or FIG. 36 are designated by the samereference numerals used in FIGS. 15 and 36 and explanations thereof willbe omitted.

In FIG. 37, regarding downlink, a case will be described in whichaggregation is performed concurrently using LTE-A and a WLAN in the WLANstandalone configuration using the secondary eNB 323 having eNB and WLANcommunication functions, with the eNB 321 serving as a master eNB. Inthis case, the GTP tunnels 1520 to 152 n are provided for each of theEPS bearers between the eNB 321 and the secondary eNB 323.

The PDCPoIP processing units 3610 to 361 n depicted in FIG. 3 areestablished in the secondary eNB 323 in an example depicted in FIG. 37.The secondary eNB 323 receives IP packets transmitted from the UE 311via the WLAN 1550. The secondary eNB 323 transfer the received IPpackets to the PDCPoIP processing units 3610 to 361 n of the virtual GW3010.

Similar to the example depicted in FIG. 36, this enables the EPS bearersto be identified as virtual IP flows in the virtual GWs 3010, 3040.Thus, without configuring the restriction that EPS bearers having thesame QoS class are not to be aggregated at the same time, the wirelesscommunications system 300 makes aggregation possible and can facilitatean increase in the amount of user data that can be transferred.

Although the downlink has been described in FIG. 37, a similar method isapplicable to the uplink, for identification of EPS bearers. That is, bybuilding a virtual IP network between the virtual GWs 3010 and 3040configured in the eNB 321 and UE 311, EPS bearers of IP packetstransferred to the WLAN can be identified in the uplink.

According to the method using the address conversion by PDCPolP depictedin FIGS. 36 and 37, the EPS bearers may be identified without the numberof EPS bearers transferrable to the WLAN being restricted by the bitnumber of the VLAN tag, as in the case of using the VLAN tag, forexample. According to the method using the address conversion by PDCPolPdepicted in FIGS. 36 and 37, connection between the eNB 321 and thesecondary eNB 323 is possible by Ethernet, etc. and is not limited tothe GTP tunnels.

According to the method using the address conversion by PDCPolP depictedin FIGS. 36 and 37, the EPS bearers can be identified withoutconfiguring a DL TFT in the UE 311 and without configuring a UL TFT inthe eNB 321. According to the method using the address conversion byPDCPoIP depicted in FIGS. 36 and 37, the EPS bearers can be identifiedwithout adding a header such as the VLAN tag to the user datatransferred to the WLAN.

In this manner, according to the third embodiment, aggregationconcurrently using LTE-A and a WLAN becomes possible without configuringthe restriction that EPS bearers having the same QoS class are not to beaggregated at the same time. Therefore, an increase in the amount ofuser data that can be transferred can be facilitated.

However, in the downlink from the eNB 321 to the UE 311, user datareceived as radio bearers by the UE 311 may be forwarded to an upperlayer (e.g., application layer) without conversion to bearers. In such acase, even though plural EPS bearers have the same QoS class,aggregation concurrently using LTE-A and a WLAN can be performed withoutthe UE 311 identifying the bearers.

FIGS. 38 and 39 are diagrams describing processing for data transmittedby a WLAN in the wireless communications system according to a fourthembodiment. A protocol stack depicted in FIG. 38, as in the second andthird embodiments, depicts processing performed in the order of a PDCPlayer 3801 (PDCP PDU), an outer IP layer 3802, and a WLAN MAC layer 3803(WLAN MAC) with respect to the data transmitted by the WLAN.

In the embodiments described above, although the wording “outer IP” isused for the sake of convenience, the outer IP is technically, simply,IP (Internet Protocol), and similarly in the present embodiment.

The PDCP layer 3801 corresponds to, for example, the PDCP layer in theaggregation processing 1212 depicted in FIG. 12, the PDCP layer 1901depicted in FIGS. 19 to 24, etc. The outer IP layer 3802 corresponds to,for example, the outer IP processing in the aggregation processing 1212depicted in FIG. 12, the outer IP layer 1900 depicted in FIGS. 19 to 24,etc. The MAC layer 3803 corresponds to, for example, 0.11×MAC processingin the aggregation processing 1212 depicted in FIG. 12.

In the protocol stack depicted in FIG. 38, the MAC address of thedestination of the data can be obtained from the IP address of thedestination of the data by, for example, an Address Resolution Protocol(ARP) under IP when data is transmitted by the WLAN, by using the outerIP layer 3802. ARP, for example, is ARP defined by RFC826. In this case,a WLAN node (e.g., the eNB 321, the secondary eNB 323), for example, canoperate by a mode like a router.

A protocol stack depicted in FIG. 39 depicts processing for datatransmitted by a WLAN in the wireless communications system 300according to the fourth embodiment. Like the protocol stack depicted inFIG. 39, in the wireless communications system 300 according to thefourth embodiment, processing of the PDCP layer 3801, processing of anadaption layer 3901 (Adaptation Layer), and processing of the WLAN MAClayer 3803 are performed for the data transmitted by the WLAN. In theprocessing depicted in FIG. 39, after the processing of the PDCP layer3801, the adaption layer 3901 adds a predetermined header to packetstransmitted by the WLAN and transfers the packets to the WLAN wherebythe packets are transmitted by tunneling.

In this manner, configuration may be such that the processing of theadaption layer 3901 is performed for the data transmitted by the WLAN,instead of the processing of the outer IP layer 3802. Such processing asdepicted in FIG. 39, for example, may be effective depending on LTE-WLANarchitecture requirements and problems in the transmission of IP packetsin the WLAN.

However, in the processing depicted in FIG. 39, the MAC address cannotbe obtained from the IP address by using the ARP in IP. In contrast, forexample, by providing processing of the ARP based on RFC826 in theadaption layer 3901, the MAC address can be obtained from the IP addressby using the ARP in the adaption layer 3901. In this case, a WLAN node(e.g., the eNB 321, the secondary eNB 323), for example, operates by amode like a bridge.

For example, in the ARP based on RFC826, an upper layer of the ARP isspecified by “EtherType” of Ethernet. In the current 3GPP protocols,“EtherType” is not defined; however, in 3GPP protocols, in a case wherea new “EtherType” is specified, ARP based on RFC826 can be applied tothe adaption layer 3901.

However, it is conceivable that ARP based on RFC826 may be difficult toapply to the adaption layer 3901. In contrast, a method of independentaddress resolution may be used and not application of a RFC826-based ARPto the adaption layer 3901. In this case, a WLAN node (e.g., the eNB321, the secondary eNB 323), for example, operates by a mode like abridge. Hereinafter, architecture of this method of independent addressresolution will be described.

FIG. 40 is a sequence diagram depicting an example of processing in thewireless communications system according to the fourth embodiment FIG.21 is a diagram depicting another example of implementation of the outerIP layer using a 3GPP protocol in the second embodiment. In the wirelesscommunications system 300 according to the fourth embodiment, forexample, address resolution is implemented by an execution of the stepsdepicted in FIG. 40. A communications apparatus 4001 depicted in FIG. 40is a source that transmits data to the UE 311, via the eNB 321. Forexample, the communications apparatus 4001 is the PGW 332, etc. of thepacket core network 330.

In FIG. 40, data transmitted from the communications apparatus 4001 tothe UE 311 via a WLAN is described. In this case, a transmission pathbetween the communications apparatus 4001 and the eNB 321 is an IPnetwork and a transmission path between the eNB 321 and the UE 311 isLTE-A. Further, in the example depicted in FIG. 40, a WLAN standaloneconfiguration using the secondary eNB 323 having eNB and WLANcommunication functions and in which the eNB 321 acts as a master eNBwill be described.

First, the eNB 321 transmits to the UE 311, RRC connectionreconfiguration that includes LTE-WLAN configuration for configuringLTE-WLAN aggregation (step S4001). Next, the UE 311 transmits to the eNB321, RRC connection reconfiguration complete for the RRC connectionreconfiguration (step S4002). Further, the UE 311 stores the MAC addressof the UE 311 to the RRC connection reconfiguration complete transmittedat step S4002.

Next, the eNB 321 transmits to the secondary eNB 323 that is a WLANnode, WLAN addition request for WLAN configuration in the LTE-WLANaggregation (step S4003). Further, the eNB 321 stores to the WLANaddition request transmitted at step S4003, configuration informationthat includes the MAC address of the UE 311 acquired from the RRCconnection reconfiguration complete received at step S4002.

In response, the secondary eNB 323 associates and stores the MAC addressof the UE 311 acquired from the WLAN addition request from the eNB 321,with the IP address of the UE 311.

Next, the communications apparatus 4001 is assumed to transmit to theeNB 321, data destined for the UE 311 (step S4004). Data 4010 is thedata transmitted at step S4004. The data 4010 includes a source IPaddress 4011, a destination IP address 4012, and IP payload 4013. Thesource IP address 4011 is the IP address of the communications apparatus4001 that is the source of the data 4010. The destination IP address4012 is the IP address of the UE 311 that is destination of the data4010. The IP payload 4013 is the payload (e.g., user data) of the data4010. In actuality, since the IP packet is transmitted by a GTP tunnel,a GTP is added; however, description is omitted herein.

Next, the eNB 321 converts the data received at step S4004 into PDCPPDUs and transfers the PDCP PDUs to the secondary eNB 323 (step S4005).Next, the secondary eNB 323 transmits by the WLAN (IEEE MAC) to the UE311, the data transmitted and converted to the PDCP PDUs at step S4005(step S4006). Data 4020 is the data transmitted at step S4006.

The data 4020 is data to which a destination MAC address 4021 and asource MAC address 4022 are added as a header to the source IP address4011, the destination IP address 4012 and the IP payload 4013 of thedata 4010. The PDCP PDUs are included in the IP payload. The destinationMAC address 4021 is the MAC address of the UE 311 stored by thesecondary eNB 323 at step S4003. The source MAC address 4022 is the MACaddress of the secondary eNB that is the source of the data 4020.

As depicted in FIG. 40, in the LTE-WLAN aggregation, when the eNB 321transmits the RRC connection reconfiguration to the UE 311, the UE 311stores the MAC address of the UE 311 to the response signal. As aresult, the eNB 321 and the secondary eNB 323 become capable ofacquiring the MAC address of the UE 311 without using ARP of IP. In thismanner, for example, resolution of the MAC address can be performedusing a RRC message.

Although configuration of a WLAN standalone configuration using thesecondary eNB 323 having the eNB and WLAN communication functions, withthe eNB 321 serving as a master eNB has been described, configurationmay be such that the eNB 321 has the WLAN communication function and thesecondary eNB 323 is not used. In this case, for example, step S4003becomes unnecessary and the eNB 321 associates and stores the MACaddress of the UE 311 with the IP address of the UE 311.

The eNB 321 transmits to the UE 311, the data 4020 that is obtained byadding the destination MAC address 4021 and the source MAC address 4022to the data 4010 received from the communications apparatus 4001. Thesource MAC address 4022 in this case is the MAC address of the eNB 321,which is the source of the data 4020.

Further, although downlink data transmitted from the communicationsapparatus 4001 to the UE 311 has been described, similarly for uplinkdata from the UE 311 to the communications apparatus 4001, theresolution of the MAC address can be performed using a RRC message. Forexample, the eNB 321 stores to the RRC connection reconfigurationtransmitted by the communications apparatus 4001, the MAC address of thesecondary eNB 323. The MAC address of the secondary eNB 323 may bestored by the eNB 321 when the eNB 321 and the secondary eNB 323 connectwith each other, or may be acquired by the eNB 321 as a result of theeNB 321 making an inquiry to the secondary eNB 323.

The UE 311 associates and stores the MAC address of the secondary eNB323 acquired from the RRC connection reconfiguration from the eNB 321with the IP address of the secondary eNB 323. The UE 311, whentransmitting data destined for the communications apparatus 4001 by theWLAN, uses the stored MAC address of the secondary eNB 323 as thedestination and transmits the data to the secondary eNB 323. In thismanner, for uplink data from the UE 311 to the communications apparatus4001, the resolution of the MAC address can be performed using a RRCmessage.

FIG. 41 is a sequence diagram of notification of the MAC address by adifferent RRC message in the processing in the wireless communicationssystem according to the fourth embodiment. In FIG. 41, parts identicalto those depicted in FIG. 40 are designated by the same referencenumerals used in FIG. 40 and will not again be described. In a RRCconnection establishment procedure, prior to step S4001, the UE 311transmits a RRC connection setup to the eNB 321 (step S4101). Further,the UE 311 stores the MAC address of the UE 311 to the RRC connectionsetup transmitted at step S4101. In this case, the UE 311 may store theMAC address of the UE 311 to the RRC connection reconfiguration completetransmitted at step S4002.

FIG. 42 is a sequence diagram of notification of the MAC address by adifferent RRC message in the processing in the wireless communicationssystem according to the fourth embodiment. In FIG. 42, parts identicalto those depicted in FIG. 40 are designated by the same referencenumerals used in FIG. 40 and will not again be described. The UE 311transmits to the eNB 321, a RRC message that is different from the RRCconnection reconfiguration complete and the RRC connection setup afterstep S4002 (step S4201). Further, the UE 311 stores the MAC address ofthe UE 311 to the RRC message transmitted at step S4201. In this case,the UE 311 may store the MAC address of the UE 311 to the RRC connectionreconfiguration complete transmitted at step S4002.

As depicted in FIGS. 41 and 42, the RCC message used for givingnotification of the MAC address of the UE 311 is not limited to the RRCconnection reconfiguration complete and various types of RRC messagescan be used.

FIG. 43 is a sequence diagram of another example of processing in thewireless communications system according to the fourth embodiment. InFIG. 43, parts identical to those depicted in FIG. 40 are designated bythe same reference numerals used in FIG. 40 and will not again bedescribed. In the wireless communications system 300 according to thefourth embodiment, address resolution is implemented by an execution ofthe steps depicted in FIG. 43.

Steps S4301 to S4305 depicted in FIG. 43 are identical to steps S4001 toS4005 depicted in FIG. 40. However, at step S4302, the UE 311 may storethe MAC address of the UE 311 to the RRC connection reconfigurationcomplete. Further, at step S4303, the eNB 321 may store the MAC addressof the UE 311 to the WLAN addition request.

Subsequent to step S4305, the eNB 321 causes operation under the ARPwith the UE 311 by the adaption layer 3901 (step S4306). The eNB 321notifies the secondary eNB 323 of the MAC address of the UE 311 acquiredby the ARP. As a result, the secondary eNB 323 can acquire the MACaddress of the UE 311.

Alternatively, at step S4306, operation under the ARP may be performedbetween the secondary eNB 323 and the UE 311. As a result, the secondaryeNB 323 can acquire the MAC address of the UE 311.

The ARP at step S4306 can be, for example, an ARP originally designed atthe adaption layer 3901 and not the ARP based on RFC826. The secondaryeNB 323 can use an ARP packet to make an inquiry to the UE 311 for theMAC address. The ARP will be described hereinafter (e.g., refer to FIG.44). The sequence of step S4305 and step S4306 may be interchanged.

Next, the secondary eNB 323 transmits to the UE 311 by a WLAN (IEEEMAC), the data converted into PDCP PDUs and transferred at step S4305(step S4307). The data transmitted at step S4307, for example, is thesame as the data 4020 depicted in FIG. 40. The destination MAC address4021 in this case is the MAC address of the UE 311 acquired by thesecondary eNB 323 by the ARP under operation at step S4306.

As depicted in FIG. 43, when the eNB 321 configures the LTE-WLANaggregation in the secondary eNB 323(WLAN node), the adaption layer 3901operates under an original ARP whereby acquisition of the MAC address ofthe UE 311 becomes possible. In this manner, for example, at theadaption layer 3901, the originally designed ARP can be used to resolvethe MAC address.

Although configuration of the WLAN standalone configuration using thesecondary eNB 323 having the eNB and WLAN communication functions, withthe eNB 321 serving as a master eNB has been described, configurationmay be such that the eNB 321 has the WLAN communication function and thesecondary eNB 323 is not used. In this case, for example, step S4305becomes unnecessary and the eNB 321, at step S4306, operates under theARP. As a result, the eNB 321 can acquire the MAC address of the UE 311.

The eNB 321 transmits to the UE 311, the data 4020 obtained by addingthe destination MAC address 4021 and the source MAC address 4022 to thedata 4010 received from the communications apparatus 4001. The sourceMAC address 4022 in this case, is the MAC address of the eNB 321 that isthe source of the data 4020.

Further, although downlink data transmitted from the communicationsapparatus 4001 to the UE 311 has been described, similarly for uplinkdata from the UE 311 to the communications apparatus 4001, theoriginally designed ARP can be used to resolve the MAC address. Forexample, when transmitting data destined for the communicationsapparatus 4001 by the WLAN, the UE 311 operates under the original ARPdescribed above and acquires the MAC address of the secondary eNB 323 bymaking an inquire to the secondary eNB 323.

The UE 311 uses the acquired MAC address of the secondary eNB 323 as thedestination to transmit uplink data to the secondary eNB 323. In thismanner, for uplink data transmitted from the UE 311 to thecommunications apparatus 4001, the originally designed ARP can be usedto resolve the MAC address.

FIG. 44 is a diagram depicting an example of a packet format in the ARPapplicable to the fourth embodiment. As depicted in FIG. 43, in theoriginally designed ARP at the adaption layer 3901, for example, apacket 4400 depicted in FIG. 44 can be used. In the packet 4400, “R”represents a reserved bit (Reserved).

“D/C” represents information that indicates whether the packet 4400 isany one of a data signal (data) and a control signal (control). In“D/C”, “D” (data) or “C” (control) is specified. In a case where “D” isspecified in “D/C”, this indicates that the second and subsequentpackets 4400 are PDCP PDUs. In a case where “C” is specified in “D/C”,this indicates that the second and subsequent packets 4400 are ARPcontrol information. In the example depicted in FIG. 44, since thepacket 4400 is used as an ARP packet, “C” in “D/C” is specified.

“Type” (Type) represents information that indicates whether the packet4400 is any one of a request signal and a response signal. “Type” (Type)becomes disabled in cases where “D” is specified in “D/C”. Further,“type” (Type) specifies a “request” (Request) or a “response” (Response)in cases where “C” is specified in “D/C”. “LCID” represents a LogicalChannel ID (LCID) under LTE. “C-RNTI” (Cell-Radio Network TemporaryIdentifier) is the Cell-Radio Network Temporary Identifier of the UE311.

In the example depicted in FIG. 44, since the packet 4400 is used as anARP packet, as described above, the second and subsequent packets 4400store ARP control information. For example, the secondary eNB 323 (WLANnode) that makes an inquiry for the MAC address transmits the packet4400 specifying “request” in “type”. In this case, the MAC address (48bits) of the secondary eNB 323 is stored in “the source MAC address”(Source MAC Address) of the packet 4400. Further, a broadcast MACaddress (48 bits) is stored in “destination MAC address” (DestinationMAC Address) of the packet 4400. As a result, the packet 4400 can bebroadcast to make an inquiry for the MAC address to the UE 311.

With respect to the packet 4400 (request) from the secondary eNB 323,the UE 311 can determine that the packet 4400 is addressed to the UE 311based on the “C-RNTI” of the packet 4400 and thus, can receive thepacket 4400. The UE 311, when receiving the packet 4400 from thesecondary eNB 323, transmits the packet 4400 specifying “response” in“type”. In this case, the MAC address of the UE 311 (48 bits) is storedin “source MAC address” of the packet 4400. Further, the MAC address ofthe secondary eNB 323 is stored in “destination MAC address”(Destination MAC Address) of the packet 4400. As a result, the secondaryeNB 323 can be notified of the MAC address of the UE 311.

However, in the originally designed ARP in the adaption layer 3901, apacket of a format of various forms can be used without limitation tothe packet 4400 depicted in FIG. 44. For example, in the adaption layer3901, destination identification information like “C-RNTI” together with“source MAC address” and “destination MAC address” may be included inthe originally designed ARP. Further, in a case in which it is judgedthat the UE can be identified by only the MAC address, “C-RNTI” may beomitted.

In this manner, according to the fourth embodiment, for example, in acase in which the EPS bearers 1500 to 150 n are divided for LTE-A and aWLAN and transmitted, PDCP packets transmitted by the WLAN can betransmitted by tunneling by the adaption layer 3901. As a result, at thereceiver, data transmitted by the WLAN can be received as PDCP packetsand the PDCP sequence numbers can be used to perform sequence controlbetween the packets received by LTE-A and the packets received by theWLAN. Therefore, data transmission that concurrently uses LTE-A and aWLAN becomes possible.

Further, the receiver station can store to a RRC (radio resourcecontrol) message transmitted to the transmitter station, the MAC addressof the receiver station usable in the WLAN (second wirelesscommunication). As a result, when data is to be transmitted using theWLAN, the transmitter station can set the MAC address acquired from theRRC message as the destination address and transmit the data to thereceiver station. Therefore, in the tunneling, even in cases where theadaption layer 3901 is used without using IP (the outer IP), resolutionof the MAC address becomes possible.

Alternatively, when data is to be transmitted using the WLAN, thetransmitter station can transmit to the receiver station, a first packetrequesting the MAC address of the receiver station usable in the WLAN.In this case, in response to the first packet from the transmitterstation, the receiver station can transmit to the transmitter station, asecond packet that includes the MAC address of the receiver station. Asa result, the transmitter station can transmit to the receiver station,data for which the MAC address of the receiver station acquired from thesecond packet from the receiver station is set as the destinationaddress. Therefore, in the tunneling, even in a case in which theadaption layer 3901 is used without using IP (the outer IP), resolutionof the MAC address becomes possible.

The fourth embodiment can be suitably implemented in combination withthe first to third embodiments.

As described, according to the wireless communications system, the basestation, the mobile station, and the processing method, datatransmission concurrently using the first wireless communication and thesecond wireless communication can be performed. For example, aggregationconcurrently using LTE-A and WLAN becomes possible whereby thetransmission rate of user data can be improved.

Further, assuming that when aggregation that concurrently uses LTE-A anda WLAN is performed and the ToS field cannot be referred to in the WLAN,for example, it is conceivable that all of the traffic is regarded asbest effort. However, in this case, QoS control cannot be performedaccording to the nature of the traffic. For example, VoLTE traffic alsobecomes best effort whereby the VoLTE communication quality degrades.

In contrast, according to the embodiments described above, an outer IPheader is added to data that is to be transferred to the WLAN whereby inthe WLAN, the ToS field can be referred to and QoS control performedaccording to the nature of the traffic becomes possible. For example,VoLTE traffic is classified to voice (VO) and preferentially transmittedby the WLAN whereby the VoLTE communication quality can be improved.

Further, under 3GPP LTE-A, in view of fifth generation mobilecommunication, in order to handle increasing mobile traffic and improveuser experience, the study of an enhanced system is advancing so as toenable cellular communication in conjunction with other wirelesssystems. A particular issue is cooperation with a WLAN that is widelyimplemented not only in households and companies but also insmartphones.

In LTE Release 8, a technique of offloading user data to WLAN in anLTE-A core network has been standardized. In LTE Release 12, offloadinghas become possible taking into consideration WLAN wireless channelutilization rate or user inclination to offload. Dual connectivity forconcurrent transmission of user data through aggregation of frequencycarriers between LTE-A base stations has also been standardized.

In LTE-A Release 13, study of license assisted access (LAA), which is awireless access scheme utilizing an unlicensed frequency band, has beeninitiated. LAA is a technique of layer 1 and is a carrier aggregation ofthe unlicensed frequency band and a licensed frequency band in LTE-A andcontrols wireless transmission of the unlicensed frequency band by LTE-Acontrol channel.

Unlike LAA, standardization is also about to start for aggregating LTE-Aand WLAN by the layer 2 to perform cooperative cellular communication.This is called LTE-WLAN aggregation. The LTE-WLAN aggregation has thefollowing advantages as compared to the methods described above.

In the aggregation technology in the core network, high-speedaggregation according to the LTE-A radio quality is difficult, bringingabout overhead of the control signal sent to the core network in thecase of aggregation. Since the aggregation is carried out by the LTE-Alayer 2 in the LTE-WLAN aggregation, the LTE-A radio quality can berapidly reflected and control signals to the core network areunnecessary.

Although high-speed aggregation according to the LTE-A radio quality ispossible in LAA, aggregation in cooperation with WLANs other than thoseof the LTE-A base stations is difficult. On the contrary, in LTE-WLANaggregation, cooperative aggregation becomes possible by connecting theLTE-A base stations and already configured WLAN access points on thelayer 2 level.

Currently, standardization is about to be promoted assuming not only ascenario that WLANs are incorporated into the LTE-A base stations, butalso a scenario that the WLANs are independent. In this case, it becomesimportant to identify a LTE-A call (bearer) on the WLAN side and toestablish a layer 2 configuration enabling user data transmission takingthe QoS class of the LTE bearers into account. To this end, it isnecessary to ensure LTE-A backward compatibility and not to impact tothe WLAN specifications. In this regard, for example, although a methodof encapsulating IP flows before reaching the layer 2 is alsoconceivable, the configuration of the layer 2 enabling the LTE-A bearersto be identified on the WLAN side leaves room for consideration.

According to the embodiments described above, aggregation concurrentlyusing LTE-A and WLAN becomes possible while taking the QoS classes ofthe LTE bearers into account, by contriving the tunneling method of thePDCP packets obtained in the LTE-A layer 2.

However, with the conventional techniques above, when a first wirelesscommunication of LTE, etc. and a second wireless communication of aWLAN, etc. are concurrently used to transmit data, it is difficult tocontrol sequencing between the data received by the first wirelesscommunication and data received by the second wireless communication ofthe receiving side. Therefore, in some cases, data transmissionconcurrently using the first wireless communication and the secondwireless communication cannot be performed.

According to one aspect of the present invention, an effect is achievedin that data transmission that uses the first wireless communication andthe second wireless communication can be performed.

(Note 1) A wireless communications system comprising:

-   -   a base station configured to control by a control unit        configured to control a first wireless communication, a second        wireless communication different from the first wireless        communication; and    -   a mobile station capable of data transmission with the base        station using the first wireless communication or the second        wireless communication, wherein    -   in a case where data is transmitted between the base station and        the mobile station by using the second wireless communication, a        processing unit that is for performing the first wireless        communication and that is the processing unit at a transmitter        station among the base station and the mobile station and        transmitting to a receiver station among the base station and        the mobile station by performing tunneling processing, the data        after convergence layer processing of a convergence layer for        performing the first wireless communication, and    -   the receiver station makes performing reception of data        transmitted from the transmitter station by the first wireless        communication and data transmitted from the transmitter station        by the second wireless communication, based on first wireless        communication processing possible.

(Note 2) The wireless communications system according to Note 1, wherein

-   -   the processing unit transmits to the receiver station by the        tunneling processing, a sequence number added by the convergence        layer processing,    -   the first wireless communication processing includes performing        based on the sequence number, sequence control of the data        transmitted from the transmitter station by the first wireless        communication and the data transmitted from the transmitter        station by the second wireless communication.

(Note 3) The wireless communications system according to Note 1 or 2,wherein

-   -   data is transmitted between the base station and the mobile        station by concurrently using the first wireless communication        and the second wireless communication.

(Note 4) The wireless communications system according to any one ofNotes 1 to 3, wherein

-   -   the processing unit for performing the first wireless        communication in the transmitter station, in the case where the        data is transmitted between the base station and the mobile        station by using the second wireless communication, adds to the        data after the convergence layer processing, a header that        includes service quality information and that is the header of        the data before the convergence layer processing and transmits        to the receiver station, the data to which the header is added.

(Note 5) The wireless communications system according to Note 4, whereinin the second wireless communication, transmission control based on theservice quality information is performed.

(Note 6) The wireless communications system according to Note 4 or 5,wherein

-   -   the convergence layer processing includes at least one of        ciphering for the data, header compression, and addition of the        sequence number.

(Note 7) The wireless communications system according to any one ofNotes 1 to 6, wherein

-   -   the processing unit for performing the first wireless        communication in the transmitter station, in the convergence        layer, aggregates a plurality of bearers of the mobile station        and transmits the data to the receiver station by the aggregated        bearers.

(Note 8) The wireless communications system according to any one ofNotes 1 to 6, wherein

-   -   the control unit is the plurality of bearers of the mobile        station and controls transmission of the data to the receiver        station so that each data of the plurality of bearers that have        a same service class are not transmitted concurrently using the        second wireless communication.

(Note 9) The wireless communications system according to any one ofNotes 1 to 8, wherein

-   -   in the case where the data is transmitted from the base station        to the mobile station by using the second wireless        communication, the mobile station processes the data received        using the second wireless communication without identifying a        bearer that corresponds to the data among bearers of the first        wireless communication of the mobile station.

(Note 10) The wireless communications system according to any one ofNotes 1 to 9, wherein

-   -   in the case where the data is transmitted from the base station        to the mobile station by using the second wireless        communication, the base station, with respect to the data        received by using the second wireless communication, performs        packet filtering using a filtering rule in an uplink from the        mobile station to the base station and thereby identifies a        bearer corresponding to the received data among bearers of the        first wireless communication of the mobile station.

(Note 11) The wireless communications system according to any one ofNotes 1 to 10, wherein

-   -   in the case where the data is transmitted from the base station        to the mobile station by using the second wireless        communication, the mobile station, with respect to the data        received by using the second wireless communication, performs        packet filtering using a filtering rule in a downlink from the        base station to the mobile station and thereby identifies a        bearer corresponding to the received data among bearers of the        first wireless communication of the mobile station.

(Note 12) The wireless communications system according to any one ofNotes 1 to 9, wherein

-   -   in the case where the data is transmitted from the base station        to the mobile station by using the second wireless        communication,    -   the transmitter station transmits the data by a virtual data        flow of the second wireless communication configured between the        base station and the mobile station, and    -   the receiver station identifies by a destination address of the        virtual flow receiving the data, a bearer corresponding to the        received data among bearers of the first wireless communication        of the mobile station.

(Note 13) The wireless communications system according to any one ofNotes 1 to 9, wherein

-   -   in the case where the data is transmitted from the base station        to the mobile station by using the second wireless        communication,    -   the transmitter station transmits the data by a virtual local        area communications network of the second wireless communication        configured between the base station and the mobile station, and    -   the receiver station identifies by an identifier of the virtual        local area communications network receiving the data, a bearer        corresponding to the received data among bearers of the first        wireless communication of the mobile station.

(Note 14) The wireless communications system according to any one ofNotes 1 to 9, wherein

-   -   in the case where the data is transmitted from the base station        to the mobile station by using the second wireless        communication,    -   the transmitter station transmits the data by an encapsulated        tunnel of the second wireless communication configured between        the base station and the mobile station, and    -   the receiver station identifies by a destination address of the        encapsulated tunnel receiving the data, a bearer corresponding        to the received data among bearers of the first wireless        communication of the mobile station.

(Note 15) The wireless communications system according to any one ofNotes 1 to 13, wherein

-   -   in the case where the data is transmitted from the base station        to the mobile station by using the second wireless        communication, the base station and the mobile station configure        therebetween a communication channel of the second wireless        communication for transmitting data of the first wireless        communication and transmit the data through the configured        communication channel.

(Note 16) The wireless communications system according to any one ofNotes 1 to 15, wherein

-   -   the receiver station stores to a radio resource control message        transmitted to the transmitter station, an address of the        receiver station usable in the second wireless communication,        and    -   in the case where the data is transmitted from the base station        to the mobile station by using the second wireless        communication, the transmitter station sets the address acquired        from the radio resource control message as a destination address        and transmits the data to the transmitter station.

(Note 17) The wireless communications system according to any one ofNotes 1 to 15, wherein

-   -   in the case where the data is transmitted from the base station        to the mobile station by using the second wireless        communication,    -   the transmitter station transmits to the receiver station, a        first packet requesting an address of the receiver station        usable in the second wireless communication,    -   the receiver station transmits to the receiver station in        response the first packet from the transmitter station, a second        packet that includes the address, and    -   the transmitter station sets the address acquired from the        second packet from the receiver station as a destination address        and transmits the data to the receiver station.

(Note 18) A base station capable of data transmission with a mobilestation by using a first wireless communication or a second wirelesscommunication different from the first wireless communication, the basestation comprising:

-   -   a control unit configured to control the first wireless        communication and the second wireless communication;    -   a processing unit that is a processing unit for performing the        first wireless communication and configured to transmit to the        mobile station by performing tunneling processing in a case        where data is transmitted from the base station to the mobile        station by using the second wireless communication, the data        after convergence layer processing of a convergence layer for        performing the first wireless communication.

(Note 19) A mobile station capable of data transmission with a basestation by using a first wireless communication or a second wirelesscommunication different from the first wireless communication, themobile station comprising:

-   -   a processing unit that is for performing the first wireless        communication and configured to transmit to the base station by        performing tunneling processing in a case where data is        transmitted from the base station to the mobile station by using        the second wireless communication, the data after convergence        layer processing of a convergence layer for performing the first        wireless communication.

(Note 20) A processing method by a base station capable of datatransmission with a mobile station by using a first wirelesscommunication or a second wireless communication different from thefirst wireless communication, the processing method comprising:

-   -   controlling the first wireless communication and the second        wireless communication; and    -   at a processing unit for performing the first wireless        communication, transmitting to the mobile station by performing        tunneling processing in a case where data is transmitted from        the base station to the mobile station by using the second        wireless communication, the data after convergence layer        processing of a convergence layer for performing the first        wireless communication.

(Note 21) A processing method by a mobile station base station of datatransmission with a base station by using a first wireless communicationor a second wireless communication different from the first wirelesscommunication, the processing method comprising:

-   -   at a processing unit for performing the first wireless        communication, transmitting to the mobile station by performing        tunneling processing in a case where data is transmitted from        the base station to the mobile station by using the second        wireless communication, the data after convergence layer        processing of a convergence layer for performing the first        wireless communication.

All examples and conditional language provided herein are intended forpedagogical purposes of aiding the reader in understanding the inventionand the concepts contributed by the inventor to further the art, and arenot to be construed as limitations to such specifically recited examplesand conditions, nor does the organization of such examples in thespecification relate to a showing of the superiority and inferiority ofthe invention. Although one or more embodiments of the present inventionhave been described in detail, it should be understood that the variouschanges, substitutions, and alterations could be made hereto withoutdeparting from the spirit and scope of the invention.

What is claimed is:
 1. A communication system comprising: a firstcommunication apparatus configured to control a first wirelesscommunication and a second wireless communication different from thefirst wireless communication; a second communication apparatusconfigured to communicate using the second communication; and a thirdcommunication apparatus configured to perform data communication withthe first communication apparatus via the first wireless communicationor the second wireless communication, wherein the third communicationapparatus transmits to the first communication apparatus a controlmessage that includes an available address of the third wirelesscommunications apparatus used in the second wireless communication, thefirst communication apparatus notifies the second communicationapparatus of the available address of the third communication apparatus,and the second communication apparatus communicate with the thirdcommunication apparatus using the address.
 2. The communication systemaccording to claim 1, wherein the first communication apparatus furtherincludes a controller configured to control the first wirelesscommunication and the second wireless communication.
 3. A communicationapparatus capable of communication via a first wireless communication ora second wireless communication different from the first wirelesscommunication, the communication apparatus comprising: a transmitterconfigured to transmit to a first communication apparatus via the firstwireless communication a control message that includes an availableaddress of the communication apparatus in the second wirelesscommunication; and a receiver configured to receive data transmittedusing the address by a second communication apparatus that communicatewith the communication apparatus using the second wireless communicationand is notified of the address from the first communication apparatus.4. The communication apparatus according to claim 3, wherein thereceiver receives from the first communication apparatus a requestsignal requesting the address usable in the second wirelesscommunication, and the transmitter transmits the control massageaccording to the request message.
 5. A communication apparatus capableof communication with a first communication apparatus via a firstwireless communication or a second wireless communication different fromthe first wireless communication, the communication apparatuscomprising: a receiver configured to receive from the firstcommunication apparatus via the first wireless communication a controlmessage that includes an available address of the first communicationapparatus in the second wireless communication; and a transmitterconfigured to notify the address to a second communication apparatusthat communicates with the first communication apparatus via the secondwireless communication.
 6. The communication apparatus according toclaim 5, further comprising a controller configured to controltransmission via an adaptation layer when transmitting data from thetransmitter to the second communication apparatus.
 7. The communicationapparatus according to claim 6, wherein the controller controls thetransmission of the data to which a sequence number is added throughprocessing of a convergence layer for performing the first wirelesscommunication through the adaptation layer.
 8. The communicationapparatus according to claim 5, further comprising a controllerconfigured to control transmission via an adaptation sublayer whentransmitting data from the transmitter to the second communicationapparatus.
 9. The communication apparatus according to claim 8, whereinthe controller controls the transmission of the data to which a sequencenumber is added through processing of a convergence layer for performingthe first wireless communication through the adaptation sublayer. 10.The communication apparatus according to claim 5, further comprising acontroller configured to control the first wireless communication andthe second wireless communication.